Location from pokemon-kanto by
Koga's ninja dojo in Fuchsia City — Kanto's fifth gym, full of invisible walls, mirror illusions, and Poison-type Pokémon.
Fuchsia Gym awards the Soul Badge. Trainers first have to navigate a maze of invisible walls and false doors before they even reach the battlefield — which cuts most challengers in half. Koga's Poison Pokémon (Venonat, Venomoth, Golbat) specialize in status effects. His daughter Aya challenges visitors first as a warm-up.
A sprawling traditional dojo painted purple and black with sliding rice-paper doors, tatami-floored halls, and labyrinthine corridors hidden behind mirror panels. The main arena, only reachable after solving the gym's spatial puzzles, is a square tatami with a raised platform for Koga.