The Dark Valley after the Onii have left
The Dark Valley (まっくら谷, Makkura tani) is the main region of the Onii Kingdom. After beating the Onii Man, King Corobo goes through Dark Valley via the Former Onii Grounds to fight the Onii King. The valley has various pots containing arrows and Oniis throwing pots at Corobo.
Once Corobo defeats the Onii King, Dark Valley gets renamed as "Dark Valley Nature Reserve" and is inhabited by Rodeo Cows in the valley and Black Sheep on the cliffs. Initially, this area was very dark, but becomes sunny when Corobo claims the area.
Before Onii King's defeat:
After Onii King's defeat:
Names in other languages
|French||Vallée obscure||Dark Valley|
|Italian||Valle oscura||Dark Valley|
|German||Tal der Finsternis||Valley of Darkness|