As in subject.
Fot the life of mine I can't find anything about that in the documentation nor in forums and the feature is nowhere to be found in the touch ui.
Probably, you're checking the same in TOUCH UI.
Open http://localhost:4502/siteadmin#/content -- this would enable CLASSIC UI. Then follow the links shared by Arun/Vishu. You'd see the "deleted" page under the selected parent page with an option to recover.
Login to the server on which you've deleted the page using - http://<servername>/siteadmin#/content
**This link uses "siteadmin#" and not "sites.html"
Revert in case you still face issues.
You can use the Restore version option 
 Working with Page Versions
That was it. Thank you. Much appreciated.
So simple but yet so counter intuitive and not explained anywhere in plain English.
Thanks for the quick response. Yes, we knew we can restore a page to previous versions. Restoring a deleted page is pretty different; do you know when Adobe will add this functionality? thanks.
No, but from versions, you can restore
Working with Page Versions
How can we restore a deleted page within a touch UI ( not using WCM, classic UI)? Does AEM have a concept of "Trash" can?
Yes I'm using Touch UI (even though I have Classic UI selected in my account preferences).
I don't have access to local environment. I'm an Author who is managing content on live site. Is there anything I can do to enable Classic UI there?
The links you've shared look nothing like the UI I see on my end.
I use AEM Sites 6.3 and it looks completely different and there is no Tools menu at all.
If I don't see the page to begin with how can I use any of the page versions features.
I'm new to this experience and I must be missing something embarrassingly simple here.
check below if helps:
Lost your content in AEM? This might help...
Accidentally deleted a page in AEM? Here’s how you can get it back | Adobe AEM Club
Recovering Deleted Pages - Content Management System - Simon Fraser University
Or Do you have daily backup of your VM or repository in place?