

The middle two-quarters of the Underworld contains several Ruined Houses, which are towers made from Obsidian Bricks and, less commonly, Hellstone Bricks that contain Shadow Chests, Hellforges, Pots, Obsidian furniture, and other lootable items. Further, because the Wall of Flesh is summoned by dropping a Guide Voodoo Doll into Lava, killing a Voodoo Demon positioned over Lava can inadvertently summon it. Hellstone, a valuable crafting material only obtainable in the Underworld, inflicts the Burning debuff when touched and releases half a tile of Lava when mined. The Underworld contains many hazards, such as large pools of Lava and various difficult enemies. The Wall of Flesh boss can be summoned in the Underworld defeating it will cause the world to convert to Hardmode. It also contains numerous Ruined Houses, which are natural structures containing unique furniture and loot. It is a large, open cavern that stretches across the bottom of the world, with a ceiling of Ash Blocks and a lower terrain of large Lava pools, Ash Blocks, and Hellstone. The Underworld (also known as Hell) is the deepest layer of the world.
