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.
Meridian, Horizon Zero Dawn The Citadel, Mass Effect Rapture & Columbia, BioShock A large, fully built-up island, any Anno game
Bonus: Tamriel, Skyrim, but that’s probably too large for the scope of the question
Another Bonus: Anywhere in No Man’s Sky, as long as I have a spaceship