In Pokémon Pokopia, where did humanity store Pokémon before leaving Earth?

In Pokémon Pokopia, humanity stored Pokémon in a massive computer system before leaving Earth.

The game's logs reveal that unexplained phenomena gradually made the landscape hostile to life. Humanity eventually departed for outer space, but it could not take all its Pokémon along. Instead, people placed Pokémon in a huge computer system designed to remain operational after the human departure.

The system could release selected Pokémon if it began to fail. This explains why Pokémon remain in the abandoned world and why the story connects environmental recovery with the fate of the Pokémon population.

This backstory is easy to confuse with the game's ending, where an emergency structure is revealed to be a rocket ship. The computer system is the storage solution described in the historical logs; the rocket ship is the later evacuation mechanism discovered by Ditto and Professor Tangrowth.