diff -u b/core/modules/help/help.api.php b/core/modules/help/help.api.php
--- b/core/modules/help/help.api.php
+++ b/core/modules/help/help.api.php
@@ -59,62 +59,21 @@
- * Returns information about a section for the help page at admin/help.
+ * Perform alterations on help page section plugin definitions.
  *
- * @return array
- *   Array where each element represents a section to be listed on the main
- *   help page at admin/help. The outer array key is a unique machine name
- *   for the section; each section is represented by an array with the
- *   following elements:
- *   - header: (required) Translated text for the section header.
- *   - description: (optional) Translated text for the description below the
- *     header.
- *   - permission: (optional) Permission needed to see this section, beyond
- *     the generic 'access administration pages' needed to see the admin/help
- *     page itself.
- *   - topics_callback: (required) Callable in the format of
- *     callback_help_section_list() that generates the topics list for this
- *     section.
- *   - cache: (optional) Information to be put into the #cache element of the
- *     render array for this section.
+ * Sections for the admin/help page are provided by plugins. This hook allows
+ * modules to alter the plugin definitions.
+ *
+ * @param array $info
+ *   Array of plugin information exposed by hook page section plugins, altered
+ *   by reference.
+ *
+ * @see \Drupal\help\HelpSectionPluginInterface
+ * @see \Drupal\help\Annotation\HelpSection
+ * @see \Drupal\help\HelpSectionManager
  */
-function hook_help_section_info() {
-  return [
-    'hook_help' => [
-      'header' => t('Module overviews'),
-      'description' => t('Module overviews are provided by modules. Overviews available for your installed modules:'),
-      'permission' => 'access administration pages',
-      'topics_callback' => 'help_list_hook_help_topics',
-    ],
-  ];
+function hook_help_section_info_alter(&$info) {
+  // Alter the header for the module overviews section.
+  $info['hook_help']['header'] = t('Overviews of modules');
 }
 
 /**
  * @} End of "addtogroup hooks".
  */
-
-/**
- * Generate a list of topics for hook_help_section_info().
- *
- * The name of this function name or callable is returned as 'topics_callback'
- * in a hook_help_section_info() return value.
- *
- * @return array
- *   A sorted list of topic links or render arrays for topic links. The links
- *   will be shown in the help section. If the returned array of links is
- *   empty, the section will be shown with some generic empty text.
- */
-function callback_help_section_list() {
-  // This sample callback lists the hook_help() module overview topics.
-  $topics = [];
-  $route_match = \Drupal::routeMatch();
-  $module_info = system_rebuild_module_data();
-
-  foreach (\Drupal::moduleHandler()->getImplementations('help') as $module) {
-    if (\Drupal::moduleHandler()->invoke($module, 'help', ["help.page.$module", $route_match])) {
-      $title = $module_info[$module]->info['name'];
-      $topics[$title] = Link::createFromRoute($title, 'help.page', ['name' => $module]);
-    }
-  }
-
-  // Sort topics by title, which is the array key above.
-  ksort($topics);
-  return $topics;
-}
diff -u b/core/modules/help/help.module b/core/modules/help/help.module
--- b/core/modules/help/help.module
+++ b/core/modules/help/help.module
@@ -6,7 +6,6 @@
  */
 
 use Drupal\Core\Block\BlockPluginInterface;
-use Drupal\Core\Link;
 use Drupal\Core\Routing\RouteMatchInterface;
 
 /**
@@ -79,41 +77,0 @@
-
-/**
- * Implements hook_help_section_info().
- */
-function help_help_section_info() {
-  return [
-    'hook_help' => [
-      'header' => t('Module overviews'),
-      'description' => t('Module overviews are provided by modules. Overviews available for your installed modules:'),
-      'permission' => 'access administration pages',
-      'topics_callback' => 'help_list_hook_help_topics',
-      // There is no cache information provided in this implementation, because
-      // the topic list comes from a list of modules implementing hook_help().
-      // If a module adds or removes hook_help() or gets installed/uninstalled,
-      // hopefully the page cache would get cleared anyway.
-    ],
-  ];
-}
-
-/**
- * Generates a list of hook_help() topics for the admin/help page.
- *
- * @return array
- *   List of links to hook_help() topics for enabled modules that implement it.
- *
- * @see help_help_section_info().
- */
-function help_list_hook_help_topics() {
-  $topics = [];
-  $route_match = \Drupal::routeMatch();
-  $module_info = system_rebuild_module_data();
-
-  foreach (\Drupal::moduleHandler()->getImplementations('help') as $module) {
-    $title = $module_info[$module]->info['name'];
-    $topics[$title] = Link::createFromRoute($title, 'help.page', ['name' => $module]);
-  }
-
-  // Sort topics by title, which is the array key above.
-  ksort($topics);
-  return $topics;
-}
diff -u b/core/modules/help/src/Controller/HelpController.php b/core/modules/help/src/Controller/HelpController.php
--- b/core/modules/help/src/Controller/HelpController.php
+++ b/core/modules/help/src/Controller/HelpController.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Url;
+use Drupal\help\HelpSectionManager;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
@@ -26,13 +27,23 @@
   protected $routeMatch;
 
   /**
+   * The help section plugin manager.
+   *
+   * @var \Drupal\help\HelpSectionManager
+   */
+  protected $helpManager;
+
+  /**
    * Creates a new HelpController.
    *
    * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
    *   The current route match.
+   * @param \Drupal\help\HelpSectionManager $help_manager
+   *   The help section manager.
    */
-  public function __construct(RouteMatchInterface $route_match) {
+  public function __construct(RouteMatchInterface $route_match, HelpSectionManager $help_manager) {
     $this->routeMatch = $route_match;
+    $this->helpManager = $help_manager;
   }
 
   /**
@@ -40,14 +51,16 @@
    */
   public static function create(ContainerInterface $container) {
     return new static(
-      $container->get('current_route_match')
+      $container->get('current_route_match'),
+      $container->get('plugin.manager.help_section')
     );
   }
 
   /**
    * Prints a page listing various types of help.
    *
-   * The page has sections defined by hook_help_section_info().
+   * The page has sections defined by \Drupal\help\HelpSectionPluginInterface
+   * plugins.
    *
    * @return array
    *   A render array for the help page.
@@ -63,41 +76,39 @@
       ],
     ];
 
-    $sections = $this->moduleHandler()->invokeAll('help_section_info');
-    foreach ($sections as $name => $info) {
-      // Skip this section if there is not a callback.
-      if (empty($info['topics_callback'])) {
-        continue;
-      }
-
+    $plugins = $this->helpManager->getDefinitions();
+    foreach ($plugins as $plugin_id => $plugin_definition) {
       // Check the provided permission.
-      if (!empty($info['permission']) && !$this->currentuser()->hasPermission($info['permission'])) {
+      if (!empty($plugin_definition['permission']) && !$this->currentuser()->hasPermission($plugin_definition['permission'])) {
         continue;
       }
 
       // Generate the links, and include the section.
       $this_output = [
         '#theme' => 'help_section',
-        '#title' => $info['header'],
-        '#description' => isset($info['description']) ? $info['description'] : '',
+        '#title' => $plugin_definition['header'],
+        '#description' => $plugin_definition['description'],
         '#links' => $this->t('There is currently nothing in this section'),
       ];
-      $links = call_user_func($info['topics_callback']);
+      /** @var \Drupal\help\HelpSectionPluginInterface $plugin */
+      $plugin = $this->helpManager->createInstance($plugin_id);
+      $links = $plugin->listTopics();
       if (is_array($links) && count($links)) {
         $this_output['#links'] = $this->fourColumnList($links);
       }
-      if (!empty($info['cache'])) {
-        $this_output['#cache'] = $info['cache'];
+      $cache = $plugin->getCacheInformation();
+      if (!empty($cache)) {
+        $this_output['#cache'] = $cache;
       }
 
-      $output[$name] = $this_output;
+      $output[$plugin_id] = $this_output;
     }
 
     return $output;
   }
 
   /**
-   * Makes a four-column list of items
+   * Makes a four-column list of items.
    *
    * @param array $items
    *   Array of string or render array items to separate into four columns.
diff -u b/core/modules/tour/src/Tests/TourHelpPageTest.php b/core/modules/tour/src/Tests/TourHelpPageTest.php
--- b/core/modules/tour/src/Tests/TourHelpPageTest.php
+++ b/core/modules/tour/src/Tests/TourHelpPageTest.php
@@ -43,8 +43,10 @@
   protected function setUp() {
     parent::setUp();
 
-    // Create users.
-    $this->tourUser = $this->drupalCreateUser(['access administration pages', 'access tour']);
+    // Create users. For the Tour user, include permissions for the language
+    // tours' parent pages, but not the translation tour's parent page. See
+    // self:getTourList().
+    $this->tourUser = $this->drupalCreateUser(['access administration pages', 'access tour', 'administer languages']);
     $this->noTourUser = $this->drupalCreateUser(['access administration pages']);
   }
 
@@ -91,6 +93,12 @@
       }
       else {
         $this->assertNoLink($title);
+        // Just test the first item in the list of links that should not
+        // be there, because the second matches the name of a module that is
+        // in the Module overviews section, so the link will be there and
+        // this test will fail. Testing one should be sufficient to verify
+        // the page is working correctly.
+        break;
       }
     }
 
@@ -102,6 +110,12 @@
       }
       else {
         $this->assertNoText($title);
+        // Just test the first item in the list of text that should not
+        // be there, because the second matches part of the name of a module
+        // that is in the Module overviews section, so the text will be there
+        // and this test will fail. Testing one should be sufficient to verify
+        // the page is working correctly.
+        break;
       }
     }
   }
@@ -121,10 +135,12 @@
    *
    * @return array
    *   A list of tour titles to test. The first array element is a list of tours
-   *   with links, and the second is a list of tours without links.
+   *   with links, and the second is a list of tours without links. Assumes
+   *   that the user being tested has 'administer languages' permission but
+   *   not 'translate interface'.
    */
   protected function getTourList() {
-    return [ ['Adding languages', 'Translation'], ['Editing languages']];
+    return [ ['Adding languages', 'Language'], ['Editing languages', 'Translation']];
   }
 
 }
reverted:
--- b/core/modules/tour/tour.module
+++ a/core/modules/tour/tour.module
@@ -5,7 +5,6 @@
  * Main functions of the module.
  */
 
-use Drupal\Core\Link;
 use Drupal\Core\Routing\RouteMatchInterface;
 
 /**
@@ -112,68 +111,3 @@
 function tour_tour_update($entity) {
   \Drupal::service('plugin.manager.tour.tip')->clearCachedDefinitions();
 }
-
-/**
- * Implements hook_help_section_info().
- */
-function tour_help_section_info() {
-  // The list of topics depends on the list cache tag for the tour entity.
-  $tags = \Drupal::entityTypeManager()->getDefinition('tour')->getListCacheTags();
-  return [
-    'tour' => [
-      'header' => t('Tours'),
-      'description' => t('Tours guide you through workflows or explain concepts on various user interface pages. The tours with links in this list are on user interface landing pages; the tours without links will show on individual pages (such as when editing a View using the Views UI module). Available tours:'),
-      'permission' => 'access tour',
-      'topics_callback' => 'tour_list_tours',
-      'cache' => ['tags' => $tags],
-    ],
-  ];
-}
-
-/**
- * Generates a list of tours for the admin/help page.
- *
- * @return array
- *   List of all available tours, with titles made into links where possible.
- *
- * @see tour_help_section_info().
- */
-function tour_list_tours() {
-  /** @var \Drupal\Core\Entity\EntityStorageInterface $tour_storage */
-  $tour_storage = \Drupal::entityTypeManager()->getStorage('tour');
-  /** @var \Drupal\tour\TourInterface[] $entities */
-  $entities = $tour_storage->loadMultiple();
-  // Sort in the manner defined by Tour (by tour title).
-  uasort($entities, ['Drupal\tour\Entity\Tour', 'sort']);
-
-  // Make a link to each tour, using the first of its routes that can
-  // be linked to. Some routes require parameters, and cannot be made into
-  // links, so use a try/catch loop to try to make a link.
-  $topics = [];
-  foreach ($entities as $entity) {
-    $title = $entity->label();
-    $id = $entity->id();
-    $routes = $entity->getRoutes();
-    $made_link = FALSE;
-    foreach ($routes as $route) {
-      try {
-        $params = isset($route['route_params']) ? $route['route_params'] : [];
-        // Generate the link HTML directly, using toString(), to catch missing
-        // parameter exceptions now instead of at render time.
-        $topics[$id] = Link::createFromRoute($title, $route['route_name'], $params)->toString();
-        $made_link = TRUE;
-        break;
-      }
-      catch (\Exception $e) {
-        // If there was an exception, just try the next route.
-      }
-    }
-    if (!$made_link) {
-      // None of the routes worked to make a link, so at least display the
-      // tour title.
-      $topics[$id] = $title;
-    }
-  }
-
-  return $topics;
-}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/help/help.services.yml
@@ -0,0 +1,4 @@
+services:
+  plugin.manager.help_section:
+    class: Drupal\help\HelpSectionManager
+    parent: default_plugin_manager
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/help/src/Annotation/HelpSection.php
@@ -0,0 +1,64 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\help\Annotation\HelpSection.
+ */
+
+namespace Drupal\help\Annotation;
+
+use Drupal\Component\Annotation\Plugin;
+
+/**
+ * Defines a Plugin annotation object for help page section plugins.
+ *
+ * Plugin Namespace: Plugin\HelpSection
+ *
+ * For a working example, see \Drupal\help\Plugin\HelpSection\HookHelpSection.
+ *
+ * @see \Drupal\help\HelpSectionPluginInterface
+ * @see \Drupal\help\HelpSectionManager
+ * @see hook_help_section_info_alter()
+ * @see plugin_api
+ *
+ * @Annotation
+ */
+class HelpSection extends Plugin {
+
+  /**
+   * The plugin ID.
+   *
+   * @var string
+   */
+  public $id;
+
+  /**
+   * The header of the help page section.
+   *
+   * @var \Drupal\Core\Annotation\Translation
+   *
+   * @ingroup plugin_translatable
+   */
+  public $header;
+
+  /**
+   * The description of the help page section.
+   *
+   * @var \Drupal\Core\Annotation\Translation
+   *
+   * @ingroup plugin_translatable
+   */
+  public $description;
+
+  /**
+   * The permission needed to view the help section.
+   *
+   * Set to '' if there is no special permission needed beyond the generic
+   * 'access administration pages' permission needed to see the admin/help page
+   * itself.
+   *
+   * @var string
+   */
+  public $permission;
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/help/src/HelpSectionManager.php
@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\help\HelpSectionManager.
+ */
+
+namespace Drupal\help;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Plugin\DefaultPluginManager;
+
+/**
+ * Manages help page section plugins.
+ *
+ * @see \Drupal\help\HelpSectionPluginInterface
+ * @see \Drupal\help\Annotation\HelpSection
+ * @see hook_help_section_info_alter()
+ */
+class HelpSectionManager extends DefaultPluginManager {
+
+  /**
+   * Constructs a new HelpSectionManager.
+   *
+   * @param \Traversable $namespaces
+   *   An object that implements \Traversable which contains the root paths
+   *   keyed by the corresponding namespace to look for plugin implementations.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
+   *   Cache backend instance to use.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler for the alter hook.
+   */
+  public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler) {
+    parent::__construct('Plugin/HelpSection', $namespaces, $module_handler, 'Drupal\help\HelpSectionPluginInterface', 'Drupal\help\Annotation\HelpSection');
+
+    $this->alterInfo('help_section_info');
+    $this->setCacheBackend($cache_backend, 'help_section_plugins');
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/help/src/HelpSectionPluginInterface.php
@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\help\HelpSectionPluginInterface.
+ */
+
+namespace Drupal\help;
+
+use Drupal\Component\Plugin\PluginInspectionInterface;
+
+/**
+ * Provides an interface defining a plugin for a section of the admin/help page.
+ *
+ * Plugins of this type need to be annotated with
+ * \Drupal\help\Annotation\HelpSection annotation, and placed in the
+ * Plugin\HelpSection namespace directory. They are managed by the
+ * \Drupal\help\HelpSectionManager plugin manager class.
+ */
+interface HelpSectionPluginInterface extends PluginInspectionInterface {
+
+  /**
+   * Returns a list of topics to show in the help section.
+   *
+   * @return array
+   *   A sorted list of topic links or render arrays for topic links. The links
+   *   will be shown in the help section; if the returned array of links is
+   *   empty, the section will be shown with some generic empty text.
+   */
+  public function listTopics();
+
+  /**
+   * Returns cache information for the help section.
+   *
+   * @return array
+   *   Cache information to be added as #cache to the render array for this
+   *   help page section. Empty array if there isn't any. See the Caching
+   *   section of the @link theme_render Render API topic @endlink for more
+   *   information.
+   */
+  public function getCacheInformation();
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/help/src/Plugin/HelpSection/HookHelpSection.php
@@ -0,0 +1,96 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\help\Plugin\HelpSection\HookHelpSection.
+ */
+
+namespace Drupal\help\Plugin\HelpSection;
+
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\StringTranslation\TranslationInterface;
+use Drupal\Core\Link;
+use Drupal\Core\Plugin\PluginBase;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\help\HelpSectionPluginInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides the module topics list section for the help page.
+ *
+ * @HelpSection(
+ *   id = "hook_help",
+ *   header = @Translation("Module overviews"),
+ *   description = @Translation("Module overviews are provided by modules. Overviews available for your installed modules:"),
+ *   permission = ""
+ * )
+ */
+class HookHelpSection extends PluginBase implements HelpSectionPluginInterface, ContainerFactoryPluginInterface {
+
+  /**
+   * The module handler.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * Constructs a HookHelpSection object.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The string_translation service.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler service.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, TranslationInterface $translation, ModuleHandlerInterface $module_handler) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->stringTranslation = $translation;
+    $this->moduleHandler = $module_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('string_translation'),
+      $container->get('module_handler')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheInformation() {
+    // There is no cache information provided in this implementation, because
+    // the topic list comes from a list of modules implementing hook_help().
+    // If a module adds or removes hook_help() or gets installed/uninstalled,
+    // hopefully the page cache would get cleared anyway.
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function listTopics() {
+    $topics = [];
+    foreach ($this->moduleHandler->getImplementations('help') as $module) {
+      $title = $this->moduleHandler->getName($module);
+      $topics[$title] = Link::createFromRoute($title, 'help.page', ['name' => $module]);
+    }
+
+    // Sort topics by title, which is the array key above.
+    ksort($topics);
+    return $topics;
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/tour/src/Plugin/HelpSection/TourHelpSection.php
@@ -0,0 +1,134 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\tour\Plugin\HelpSection\TourHelpSection.
+ */
+
+namespace Drupal\tour\Plugin\HelpSection;
+
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Link;
+use Drupal\Core\Plugin\PluginBase;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\StringTranslation\TranslationInterface;
+use Drupal\help\HelpSectionPluginInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\Core\Url;
+
+/**
+ * Provides the tours list section for the help page.
+ *
+ * @HelpSection(
+ *   id = "tour",
+ *   header = @Translation("Tours"),
+ *   description = @Translation("Tours guide you through workflows or explain concepts on various user interface pages. The tours with links in this list are on user interface landing pages; the tours without links will show on individual pages (such as when editing a View using the Views UI module). Available tours:"),
+ *   permission = "access tour"
+ * )
+ */
+class TourHelpSection extends PluginBase implements HelpSectionPluginInterface, ContainerFactoryPluginInterface {
+
+  /**
+   * The entity type manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * Constructs a HookHelpSection object.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The string_translation service.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity manager service.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, TranslationInterface $translation, EntityTypeManagerInterface $entity_type_manager) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->stringTranslation = $translation;
+    $this->entityTypeManager = $entity_type_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('string_translation'),
+      $container->get('entity_type.manager')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheInformation() {
+    // The list of topics depends on the list cache tag for the tour entity.
+    $tags = $this->entityTypeManager->getDefinition('tour')->getListCacheTags();
+    return ['tags' => $tags];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function listTopics() {
+    /** @var \Drupal\Core\Entity\EntityStorageInterface $tour_storage */
+    $tour_storage = $this->entityTypeManager->getStorage('tour');
+    /** @var \Drupal\tour\TourInterface[] $entities */
+    $entities = $tour_storage->loadMultiple();
+    // Sort in the manner defined by Tour (by tour title).
+    uasort($entities, ['Drupal\tour\Entity\Tour', 'sort']);
+
+    // Make a link to each tour, using the first of its routes that can
+    // be linked to by this user, if any.
+    $topics = [];
+    foreach ($entities as $entity) {
+      $title = $entity->label();
+      $id = $entity->id();
+      $routes = $entity->getRoutes();
+      $made_link = FALSE;
+      foreach ($routes as $route) {
+        // Some routes require parameters, and will generate exceptions. Use
+        // a try/catch loop to skip over these ones to find one that will work.
+        try {
+          $params = isset($route['route_params']) ? $route['route_params'] : [];
+          $url = Url::fromRoute($route['route_name'], $params);
+          // Skip this route if the current user cannot access it.
+          if (!$url->access()) {
+            continue;
+          }
+
+          // Generate the link HTML directly, using toString(), to catch
+          // missing parameter exceptions now instead of at render time.
+          $topics[$id] = Link::fromTextAndUrl($title, $url)->toString();
+          // If the line above didn't generate an exception, we have a good
+          // link that the user can access.
+          $made_link = TRUE;
+          break;
+        }
+        catch (\Exception $e) {
+          // Exceptions are normally due to routes that need parameters. If
+          // there is an exception, just try the next route and see if we can
+          // find one that will work for us.
+        }
+      }
+      if (!$made_link) {
+        // None of the routes worked to make a link, so at least display the
+        // tour title.
+        $topics[$id] = $title;
+      }
+    }
+
+    return $topics;
+  }
+
+}