Saffron City was Pikachu's stage in the original Super Smash Bros. for the N64, placed high on top of the skyscrapers of Saffron City.
There is a main building to stand on in the middle, with two smaller buildings on the right and left. There are also a few moving platforms to the left of the main building.
The big hazard of this stage is the Random Pokemon that come out of the top of the main building, dealing damage to whoever gets in their way. It is safe to avoid the Pokemon and stay towards the left of the stage.