Mt. Mortar (Japanese: スリバチやま Mt. Suribachi) is a large cave in Johto with three entrances on Route 42. Part of the large range of mountains north of the Johto region, it is known to be a confusing maze-like area with an interior cave known as the Waterfall Cave. Mt. Mortar has three entrances and is huge inside, one of the largest of all caves in the games. It has four floors, and its high Pokémon-encounter rate makes getting lost very costly. It has Surfable waterways, Waterfalls, Strength puzzles, and multiple levels. It is usually considered to be one of the toughest caves to navigate.