Non-natural decoration

[sofar]

Describes artifacts found in the natural world. May include buildings, roads, ruins, objects.

[gaelysam]

Maybe villages? (but start with a very simple mapgen: only scattered buildings)
At least:

• ruined houses: made of wood or stone
• small temples: made of stone, with a geometrical shape, with a pedestal at the center, which can expose a book, or something else, or can be empty. Found on places that are difficult to reach (high elevation, dense jungle, etc.)

[sofar]

Right, including structures in the underground.