Crimson Forest: Crimson wood, and vicious mushrooms can be found. Mobs here drop vertebra.

Crimson Desert: Crimson cactus, and crimson sand can be found.

Surface Chest: Can be found from layers 90-50, they spawn surface chest.

Underground Chest: Can be found from layers 50-30, they spawn underground chest.

Cavern Chest: Can be found from layers 30-0, they spawn cavern chest.

Meteorite Impacts: Can be found rarely in plains and cold plains biomes. They contain meteorite blocks that can be crafted into phase blades and space guns.

Dungeons: Cannot currently be found naturally. In order to have it spawn you must give your self a structure block with /give @s structure_block using cheats. The name of the structure is mystructure:dungeon. Dungeons contain rare loot that only spawns there called Golden Chest (Dungeon). You can open them with golden keys which drops from mobs found in the dungeon. Right Click the old man to summon the Skeletron boss.