[adma]

I've never been to this place. Are there little plaques describing these stone remnants and where they came from?

For the most part, yes.

This place must have been AMAZING!

I was going to go on an Adventure there, but just realized everything worth seeing -- crazy 60's hotel, historic hotel -- is gone

It's pretty shallow IMO to think that the "crazy 60's hotel" was "everything worth seeing" there, given that the older part of the Inn as well as the landscape setting is still extant. Though I do agree that, given the cult following the 60s wing's acquired among pop-modern enthusiasts, a more imaginative solution could have been arrived at other than blithely writing it off...