Creating an alternate path for a page

I would like to load the same page under a different URL, but not via a redirect.

For example, suppose I create some page with id=6 - I can access this page via example.com/index.php?page_id=6 - if Im using pretty permalinks, I can give this page a path like /mypage and it will also be accessible at example.com/mypage.

But what if I want to access this page at example.com/alsomypage?

In other words, both example.com/mypage and example.com/alsomypage will load the content given by example.com/index.php?page_id=6 but without using a redirect.

Is something like this possible?