you can't its for catching jhoto Pokemon
You have to beat the elite 4.
Altering cave is on 5 or 6 island.
There is no Altering Cave in Pokémon Platinum.
You can't do anything with altering cave unless you have an E Reader.
There are no moveable rocks in Altering Cave.
It's normally no pokémons in the altering cave i heard that you must do something ;)
Altering cave does not change into traveler's cave. Altering cave can only offer new Pokemon (since all it offers are zubat) after using Mystery Gift.
Through Min Settings in mystery Gift
No.
Only zubat can be found in Altering Cave. Altering Cave was a location intended to be used for an event where Mystery Gifts could change the pokemon encountered in the cave, but these Mystery Gifts were never officially distributed.
You can't get to the Altering Cave in Pokémon Pearl because there is no such thing in Pearl.
Altering CaveIn Emerald, FireRed, and LeafGreen, Altering Cave appear useless for only having Zubat. If you go to a Nintendo Event with a Wireless Adapter attached, you'll get to catch rare Johto Pokemon.