Rules: only places that don’t exist, so no “NY from Spider-Man” also if you can limit to a building or little town, not an entire city or map.
My pick: The Spencer Mansion from 1996 Resident evil. I always loved that place. Of course without the creatures.
Kanto is heavily based on the real similarly named region of Japan
Still different enough to count, I’d say. Besides, the real Kanto doesn’t have pokemons