Pokemon Gold - Mt. Mortar

Mt. Mortar 

There are three entrances to this dungeon along Route 42, but you'll want to take the one in the middle. Make sure to have Pokemon with you that have S
urf, Flash and Waterfall. Also, if you want to take advantage of the opportunity to get a new Pokemon, make sure to take only five Pokemon with you (leave one slot open in

your team). 

This big dungeon is full of twisting tunnels and various other obstacles, as well as an abundance of wild Pokemon. In particular, this is the only place to catch Marill, but it is extremely rare unless swarming (trade phone numbers with Hiker Parry on Route 45 for news of this event). There are item balls scattered all over the place here, so take the time (as tedious as it will prove to be) to find all of them (if you want them, that is). All in all, you'll find: Ether, Guard Spec, Elixir, Rare Candy, Dragon Scale, Two Escape Ropes, Max Potion, Max Revive, Two Super Potions, Full Heal  and TM40 (Defense Curl).

    The real treasure here comes when you battle Kiyo, the karate master from Red/ Blue/ Yellow. When you defeat him, he rewards you with Tyrogue (provided you left an open slot in your team, of course). This is the "baby" form of all the "Hitmon­" Pokemon, including the new Hitmontop. It will evolve into one of the three at level 20, based on its Attack and Defend stats: if Attack is higher, it becomes Hitmonlee; a higher Defend results in Hitmonchan; if they are equal it becomes Hitmontop. Once you get this Pokemon up to level 19, use Protein or Iron to adjust its stats so you get the "Hitmon­" you are looking for.

Trainers 

Black Belt Kiyo: Hitmonlee (34), Hitmonchan (34)