If you just want to get out, use an Escape Rope. If you want to get to the other side, look up the map of Ice Cave.
it is in cerulean cave
mewtwo
you can go to the mt silver
he is in a cerulean cave i beleive
in cerulean cave
You find it in Union Cave.
Cerulean Cave
Mewtwo is in cerulean cave and tough to get
you catch it in cerulean cave
escape rope or dig :)
In Mt. Silver I think. Or Cerulean Cave.
You get it on Route 27 inside the cave