You have to defeat the elite 4 then go to the cave make sure to stock up on ultra balls etc
There not in cerulean cave.
You can find the Cerulean Cave in the northwest corner of Cerulean City in Kanto in Pokemon LeafGreen. The cave contains the Pokemon Mewtwo.
in cerulean cave
in cerulean cave.
At the end of cerulean cave.
back of cerulean cave
Go to Cerulean Cave.
Cerulean cave
no but mewtwo is
Cerulean Cave.
He is at the end of cerulean cave.
you have to beat the elite four, and get the national dex. then go to cerulean city, go past the nugget bridge, and surf on the water. there is a cave,and its cerulean cave