Strange example.com/node

Hi,

I've just realised that google indexed a page on my drupal website that I was not even aware that it is existing...
the page has the url: www.example.com/node

I have clean urls module enabled, and it is working fine for some years. I do not know whether the above page was created a long time ago or only recently...

The strange part about is:
1) I did not create it
2) the content of this page is very strange: it's like a series of blocks one under the other and in each block I have the beginning of a page. There are about 5 blocks and in each one the beginning of a different page followed by a "Read more" big blue button at the bottom right.

The choice of these 5 pages for which the beginning is shown in this "/node" page is quite strange, as in I have 4 languages on my website and now I can see the /contact page in one of them, then the /contact in another language then another page with content in another language... all of them having as I mentioned above the "Read more" blue button after each block.

It looks like it's an automatically generated page, something like latest changes, but actually the /contact page was not change for many months, so it's not the last changed pages... I do not understand this mix of pages.

I checked in the source code to find which node is concerned but then I couldn't find it the source code shows:
link rel="canonical" href="http://www.example.com/node" />

I also tried the url: www.example.com/node/edit but I got "Page not found"...

I also cleaned the cache... but no change.

Do you have any idea where to start with?

Many thanks