Altering Cave - Pokemon Fire Red and Leaf Green Guide - IGN

Found north of Sixth Island, this cave only have Zubats. However, if you have an E-reader connected to a gameboy advance using Japanese E-reader cards

Three Island - Pokemon Fire Red and Leaf Green Guide - IGN

Pokemon FireRed and LeafGreen :: Full Walkthrough

Pokemon FireRed and LeafGreen :: Full Walkthrough

Pokemon FireRed/LeafGreen Walkthrough - PokeDream

Let's Play Pokemon Fire Red Part 83: Outcast Island/Altering Cave

Pokémon FireRed and LeafGreen/Six Island — StrategyWiki

PK3/WC3: Unreleased Altering Cave Pokémon - Unreleased/Beta PKM

Seafoam Islands - Pokemon Fire Red and Leaf Green Guide - IGN

Pokemon FireRed/LeafGreen Walkthrough - PokeDream

Pokémon FireRed and LeafGreen/Rock Tunnel — StrategyWiki

Pokémon FireRed and LeafGreen Versions - Bulbapedia, the community

Pokémon FireRed (GBA) - 1080p60 HD Walkthrough Part 59 - Outcast

All Ominous Stake Locations - How to Open Shrines - Pokemon