Regardless of the direction we go, here’s some inspiration from ruins and lost cultures around the world:
People seem to like theAndean/Tibetian mountain culture thing, so let's start there. Disclaimer: I don't know shit about Tibet.
The Andean cultures were very diverse and numerous. The Incans were the last ones to show up on the scene in South American before the arrival of the spanish. They conquered everything around them and carved out a huge empire, what would have been the biggest empire in the world at that time. Their heyday was around 50 yeas before the Spaniards showed up, so they are not truely a lost culture. Disease and a massive succession crisis threw their well organized empire into chaos. Them and their numerous sister and parent cultures left behind some impressive ruins
Agricultural terraces that are also fortresses:
Here's a view of that with the town below:
Here's some salt pools (that I believe are still harvested today.) Pretty cool looking!
Here’s a super nutty fortress built on a the highest mountain ridge in the :
More info here
https://en.wikipedia.org/wiki/Kuélap
Note that the particular Andean (non-incan) culture that built this fortress buried their mummified ancestors in their homes.
I’m no expert on Andean cultures, but my understanding is that many of the Andean/coastal-desert cultures would also bring their mummified ancestors out during festivals and poor them Chicha (Cornbeer.) Very non-afro-eurasian.
There were also cultures in this area and some had crazy burial practices like this:
^These contain mummies and are extremely hard to reach without climbing equipment.
Moving on from the Andes,
old-timey people did similar things somewhere in China:
In the Eurasian step, there are also these Scythian burial mounds:
https://blog.britishmuseum.org/scythians-ice-mummies-and-burial-mounds/
Super inspiring. When I read an article like this I always picture myself in this particularly uncomfortable situation: I am a gross, depraved grave robber and I spent a bunch of time digging out and melting the ice in an ancient burial mound so I could rob all of the shit out of it, only to have some mean-looking, tattooed, straw-stuffed ice-mummy on a skeletal steppe-horse come out and then completely fuck me up with his ax. Maybe he’d also just have a conversation with me, I am sure we could find a topic we’d both found interesting.
Heading over to the classics now, in the writing of Xenophon’s Anabasis, it briefly describes an army taking refuge in an ancient, fallen fortress. If I understand correctly, would have been uninhabited for about 200 years at the time the army showed up.
“From this place they marched one stage, six parasangs, to a great stronghold, deserted and lying in ruins. The name of this city was Mespila and it was once inhabited by the Medes. The foundation of its wall was made of polished stone full of shells, and was fifty feet in breadth and fifty in height. Upon this foundation was built a wall of brick, fifty feet in breadth and a hundred in height; and the circuit of the wall was six parasangs. Here, as the story goes, Medea, the king's wife, took refuge at the time when the Medes were deprived of their empire by the Persians. To this city also the king of the Persians laid siege, but he was unable to capture it either by length of siege or by storm; Zeus, however, terrified the inhabitants with thunder, and thus the city was taken. “
It’s brief but it lights up the imagination. How amazing it would be to come upon runes that have been there for 200 or more years when you’re entire purpose in life is pillage, plunder and then write a book about it.
As I said before, I know very little about Tibet, but I google imaged searched the Sky Burial thing that
@Commodore was talking about in another thread and it was pretty crazy! Looking at Tibet on google maps is pretty inspiring. It's so arid.
Onto other shit now, in the goofy old video game Chrono Trigger, there was a lost culture of magic users who left behind this weird thing:
Being a game about time traveling, you can actually go visit them.
This ancient culture called themselves the kingdom of Zeal. In their cities, there were lots of magic books, machines that didn’t make any sense and weird blue guys that would interpret your dreams or something, I can't remember. They also had lots of teleportation devices.
To answer some of the questions:
What the hell are they? Unusual, magical humans would be most interesting to me.
What ridiculous name are we going to call them? The lost ones is great, I don't think they need a specific name
What did they do day-to-day? Building on the seed-vault idea, Maybe they have some kind of crazy agricultural mastery.
What was their alignment? (a prickly question for some, I'm sure...) Did they cover the spectrum? I think it would be most interesting if they covered a spectrum. It would certainly make finding their shit more mysterious.
I don't have much of an opinion on the other questions.
I hope you had as much fun reading this post as I had making it.