Reversal Mountain (Japanese: リバースマウンテンReverse Mountain) is a mountain located in eastern Unova. It is connected to Undella Town from the east and to Lentimas Town from the west. The Strange House is just east of Lentimas Town on the exterior of the mountain. The mountain's interior differs between versions: in Pokémon Black 2, the mountain's interior is filled with water, while in Pokémon White 2, it is filled with magma. Inside the mountain, Bianca will join the player as a Multi Battle partner.
Reversal Mountain was where Heatran used to come to cool off. If the player finds and brings the Magma Stone to the mountain's lowest floor, Heatran will appear.
Reversal Mountain's name might be based on the different conditions in the interior between the versions and the different times of eruptions, seeming to be a dormant volcano in Black 2, and an active one in White 2. However, true to its name, their respective map descriptions seem to be reversed.
When talking to Battle Girl Chan after fighting her, she says "A flood of attacks from three Pokémon... I know! "Jetstream" attack! Let's call it that." This is a reference to a famous combat formation from the anime Mobile Suit Gundam involving three units, two focusing on distanced attacks and one focusing on melee.