Mt. Chimney
Mt. Chimney (Japanese: えんとつやま Mt. Chimney) is a landmark in the Hoenn region.
In Pokémon Sapphire, Team Aqua steal a meteorite from the Meteor Falls and put it in a machine with the intention of causing the volcano to become dormant. In Pokémon Ruby, Team Magma steal a meteorite from the Meteor Falls and put it in a machine with the intention of reactivating the volcano. The situation in Pokémon Emerald is initially the same as in Pokémon Ruby. However, Team Magma has a base within the volcano, which is where Groudon makes its home prior to its battle against Kyogre.
Mt. Chimney was the location for the episode Fight For the Meteorite. The situation was the same as in the games except that the Meteor Falls were not visited and Ash and Professor Cozmo were both at the mountain at the time.
Geographic
Possibly based on Mount Aso, an active volcano in Aso, Kumamoto prefecture, Kyushu.