How does one find anything that isn't human or a monster in adventure mode?

Solution 1:

Occasionally, elves may populate originally human structures, such as fortresses. I once found a fort that was rotten with elves. Being immortal, they have populated it with at least 300 elves. The fort also housed an elf king, leading me to believe the elves had been assimilated into a human civilization, then the humans died out, leading to a civilization of city elves.