Safari it evoles quicker
the north west part
I don't think you can find rhydon itself, I think you have to find a ryhorn, which can be found at victory road, about level 45, or somewhere around there (forgot what level exactly) and it evolves into rhydon at level 49, but, (from another answer I heard (not wanting to take credit for it)) wait till it gets to level 55 first so give it everstone to stop it evolving because it learns earthquake at 55 where rhydon learns it a 65. Earthquake is the best ground move in the game.
By lillycove
You can't. Safari Zone 2 is only available in Emerald. Sorry.
Look in some caves, you'll eventually find one. It's also found in the Safari zone, forgot which zone though. Improved You will find it in the savanah section of the safari zone.
safari zone
You can catch a rhyhorn at the safari zone west of lilycove
It is rare on Victory Road and in the Safari Zone.
I believe a Pokemon Trainer can catch a Rhyhorn in the Safari.
Rhyhorn Is Found In The Safari Zone And Victory Road.
the north west part
Simple, you must go to the safari zone and look around
no only the safari zone emerald or safari zone in fire red and leaf green
..........level rhyhorn to 42.....get a rhyhorn from safari and evolve it to rhydon
There is girafarig, oddish, pikachu, gloom, rhyhorn, houndour, goldeen, seaking, wooper, flaaffy, and more! Have fun catching pokemon!
Safari Zone
You can find Rhyhorn in the Safari Zone in Fuchsia City, and you can Rhydon (which Rhyhorn evolves into) in Mewtwo's cave. Hope this helps :)