...or, in other words, stories where ponies uncover ancient humans preserved by cryosleep or similar methods.
If there are enough of those, of course...

5122877 Try War of the Fallen Race. Be warned though, the cryo thing doesn't happen until about halfway through the story. By the way, War of the Fallen Race is one of the best stories I've ever read on this site.

5122931
Thanks for the suggestion, though the comments there aren't particularly encouraging.

5122946
I can't remember it's title, but I saw an unfinished story where some kind of ancient cryochamber was unearthed beneath the Canterlot, complete with helium atmosphere inside and everything. Damn, now I gotta find it.

5123089 No problem. Let me know how you liked it!