Fort Beast
Fort Beast is the name of a bubble fort by Oblivia's Raikou, Entei and Suicune during the Ranger Regions Arc.
While the three Pokémon had their own homes at the Wireless Tower, Daybreak Ruins and Canal Ruins respectively, the Oblivia Beasts agreed that they needed a shared base of operations to assist the J-Team from while they outed the remnants of the Pokémon Pinchers from the Oblivia Region. Using her skill with her self-developed technique, Bubble Shield, Suicune was quickly able to construct a sizeable fort like structure from a large amount of bubbles stuck together.
The fort is sizeable enough to house the three beasts, their master, Ho-Oh, and several Pokémon and trainers with room to spare.
Although initially a temporary arrangement, after the destruction of the Sky Fortress, the beasts collectively agreed that living together in once place was more convenient and moved into Fort Beast permanently. The three can be found there when not out preforming legendary duties, or assisting the Frontier Brains at Hoenn's Battle Frontier.