un cave of azela
Geodude, Dunsparce, Zubat and some water pokemon.
Go through union cave. One will require you to bring Ho-Oh, the other will require you to use a water stone in front of the tablet.
in pokemon LEAFGREEN/FIRERED you can catch them in the tanoby chambers after you unlock a puzzle in a cave in the sevault canyon called tanoby key using strengh. in pokemon GOLD/SILVER/CRYSTAL you must unlock at least one of the puzzles in ruins of the alph then unown well appear in the visitors room where you fall after after you unlock a puzzle.
You go to Ruins of Alph in Johto and solve all four puzzles of ancient pokemon, Kabuto, Ho-oh, Aerodactyl, and Omanyte. If you solve it correctly you will fall into the Unown cave and for each puzzle you solve more unowns will appear. If you solve all the puzzles you should have unlocked all the unowns and should be able to catch all of them if you have patience. (If you don't fall in the cave that means you haven't done the puzzle correctly)
in union cave you need to go down the ladder by the scientist, surf in the water and look in that cave till you find a boulder. move it and exit the cave, hop down the ledge and into the other cave. there you have it!
go from violet city to the uknown caves. solve the sliding puzzle(a kabuto) you'll fall into the cave. the uknown should appear
In Dark Cave.
un cave of azela
There is no such thing in Pokemon G/S/C.
Silver cave in Pokemon Gold is located on route 28 on the way to Mt. Silver. The player will need Cut and Surf to navigate this passage.
Go throw the diglet cave and your there.
You can find it in the Dark Cave.
curmen cave
Geodude, Dunsparce, Zubat and some water pokemon.
Go through union cave. One will require you to bring Ho-Oh, the other will require you to use a water stone in front of the tablet.
Use the flute that wakes up Pokemon.