The Rotten Vale (Japanese 瘴気の谷) is a location first introduced in Monster Hunter: World. This area is an inhospitable valley littered with the corpses of dead monsters.
- The Rotten Vale has a deadly gas that can suffocate hunters.
- This gas also makes the monsters that live in the area more aggressive than usual, even timid ones.
- Giant bone structures hang above some areas that a hunter can bring down upon monsters using their Slingers.
- Above the Rotten Vale is the Coral Highlands.
- Hunters can carve the corpses of monsters in the Rotten Vale like Legiana.
- The skeleton of a Dalamadur can be seen throughout the Rotten Vale, including the map.
- The Rotten Vale has acid puddles that damages those who stand in them.