North in six island.
You can't do anything with altering cave unless you have an E Reader.
Nothing.
altering cave,
Zubat.
Six island its in the north.
Nothing but Zubat.
Probably.
You can catch a Houndour in the Altering Cave in Pokemon FireRed.
Well normally you can only find zubat in there but the reason why its called altering cave is that you can change what you find in there by using an E reader machine and E reader cards.
Altering Cave in Pokémon FireRed on Six Island is a special cave that typically only has wild Zubat within it however during a Nintendo-sponsored event, Nintendo would be able to send you a download via the Mystery Gift feature that would change the wild Pokémon that appear in the Altering Cave. Pokémon that are capable of appearing in the Altering Cave via the Mystery Gift download are Mareep, Aipom, Shuckle, Pineco, Smeargle, Stantler, Houndour and Teddiursa however there is no way to change the Pokémon appearing in the Altering Caves due to Nintendo no longer releasing distributions for Pokémon FireRed.
The only Pokemon you can catch is Zubat.(talk about a let down)
There is no altering cave in pookemon red since the sevii islands don't exist in Pokemon red only in Pokemon firered and leafgreen in six island after going past the forest and the altering cave is also in Pokemon emerald in route 103 a cave appears after beating the elite 4.