hoo nos
The cave is called Dragon Cave and it's situated in a lake behind the city the gym is in.
it's the dragon cave.
after the 4th gym leader you go east and a guy runs out of a cave and gives it to you
NO
cerulean cave
mewtwo
they are to the right of cianwood, the cave you cannot get to to unless you use whirlpool, beating the 7th gym leader
Cerulean Cave
Dark Cave
In cerulean cave
in mt.silver cave
Southeast from the middle of the cave