Sootopolis City is the only city in Hoenn in which diving is the only way to get in and out of the place (although when you have reached it for the first time, you can come back to the place by using Fly). Its houses somehow resemble Jewish architecture. When Kyogre and Groudon were awakened by Team Aqua and Team Magma respectively, the two Pokémon appeared in the city's lake and battled each other until Rayquaza intervened and becalmed them. Sootopolis City is also the location of Hoenn's Water-type based gym.
Sootopolis City is built in the crater of an extinct volcano, which soon filled with water during rainfall. Within the city is the Cave of Origin, guarded by one of the town's citizens. The Cave of Origin is only in Pokémon Ruby and Sapphire. Sootopolis may be where the cataclysmic battle between Groudon and Kyogre was located thousands of years ago.
The city is filled with water, in which is a small island where the gym is. On the right are some buildings and the Pokémon Center, and on the left are some houses and
someone will give you the TM Brick Break, and another will give you a Wailmer Doll. The Poké Mart is also located on the left. Way in the back, you will see an old man guard the entrance to the Cave of Origin. The Gym Leader is either Wallace or Juan who will give a Rain Badge.