you don't
You can find Mewtwo in the back of Cerulean Cave.
their is not really one necesscary place to find him in cerulean cave. u just have to look around a lot.
Cerulean cave
The Cerulean Cave is in Cerulean City. You have to surf from a place around Cerulean Cape down to the Cerulean Cave. The Cerulean Cape is north of Cerulean City across the bridge.Go to the north end of the nugget bridge then left down the grass and follow the mountain to it. Btw you'll need flash and you can find Mewtwo in it.
You can find ditto in cerulean cave.
In cerulean cave
It is in Cerulean Cave.
You can find the Electrizer in Cerulean Cave after you defeat all sixteen gyms and battle the elite four for a second time.
You can find an Elictrizer in Cerulean Cave. Its deaply within so be prepeared!
After defeating all 8 kanto gyms, go in the cerulean cave. Search everywhere and you will find it.
In Kanto's Cerulean Cave.Cerulean Cave. You must have 16 badges, and rock climb.
Either its in cerulean cave or on Cinnabar island u need rock climb for cinnabar.
You get it from The Power plant use your item finder thing its by where you catch Zapdos.in cerulean cave
there is no cerulean cave in ruby
There not in cerulean cave.
You can get all the Pokemon in the cerulean cave where you find celebi below the cerulean cave.
You can find Mewtwo in the back of Cerulean Cave.