The Thorium Mod expands on many biomes found throughout vanilla Terraria, but also features one entirely new biome and one new mini-biome.
The Aquatic Depths is an underground biome that generates directly under the Ocean on the opposite side of the world's Dungeon. It is completely submerged in water, and any attempts to create pockets of air will damage the player. This, plus the wide variety of aquatic enemies, makes this biome difficult to navigate if unprepared. However, the biome features a wide variety of loot, including Aquaite and Depth Chests for the player to obtain. After Plantera has been defeated, Aquatic Hallucinations will begin to spawn, which allows for the summoning of Abyssion, The Forgotten One, a dangerous boss. Defeating Abyssion allows for the player to naturally breath the waters of the Aquatic Depths.
The Blood Chamber is a large structure that generates in the Caverns. Only one spawns per world, and the Grim Pointer can be used to direct the player to its location. It contains a Blood Altar in its center, which summons the Viscount boss if interacted with while holding 5 Unholy Shards in the player's inventory.
|Surface Layers||Forest • Desert • Ocean • Snow biome • The Corruption • The Crimson • The Hallow|
|Underground Layers||Aquatic Depths • Cavern • Dungeon • Ice biome • Underground Desert • Underground Jungle • Underground Mushroom • Underground Hallow • The Underworld|
|Mini-Biomes and Structures||Blood Chamber • Floating Island • Granite Cave • Lihzahrd Temple • Marble Cave • Meteorite • Spider Cave|