Ruined Portal

Ruined portals are naturally generated damaged nether portals, which spawn in both the Nether and the Overworld.

Generation
Ruined portals generate in all biomes in both the Nether and the Overworld. They can spawn underground (partially or fully), underwater, or exposed to the air. The underside of the structure forms a sort of stalactite shape.

Structure
Ruined portals generate incomplete portal frames composed of both obsidian and crying obsidian, despite the latter not being a valid portal material.

They generate with one or two chests, which contain various materials and gold gear, which is sometimes enchanted.

If it generates in the Overworld it will be surrounded with stone and stone bricks and related blocks; if in the Nether it will be surrounded by blackstone materials.