Ancient eerie structure built entir...

Ancient eerie structure built entirely from bone. Large, imposing and monolithic — a single massive ossuary or catacomb building floating in darkness. Walls and architecture constructed from bone blocks and fossil stone, organic and unsettling. Arched doorways, ribbed vaulted ceilings visible from outside. Weathered and ancient, like something that grew rather than was built. No modern elements — purely primordial and skeletal. Dark, silent, deeply wrong.