once you get into the cave go through it and catch mewtwo i recomend saving in front of him i tried to catch him with a ultra ball like 10 times and couldent catch him but, i had to use a master ball.
Cerulean Cave
You can get Mewtwo in the Cerulean Cave.
Cerulean cave
mewtwo is in cerulean cave
Cerulean cave located near cerulean city.
inside cerulean cave near cerulean city.
The Cerulean Cave
You can find Mewtwo in the Cerulean Cave.
You can find ditto in cerulean cave.
In Cerulean cave in Pokemon firered and leafgreen
If you mean, "Wobbuffet", you can catch it in Cerulean Cave.
you can catch mewtwo at cerulean cave