FireRed and LeafGreen Walkthrough part II

Pewter City
Pewter City is a quiet city nestled in the northern mountains. Local attractions include the Pewter Museum of Science and the Pewter Gym. The Gym Leader is looking for challengers, and the kid blocking the city's east exit will drag the player to the Gym if they try to leave. This is the second city to sell Potions (Viridian city sells them once Oak'sParcel is delivered to him), so stock up at the Poké Mart before challenging the Gym.

Pewter Museum of Science
The Pewter Museum of Science is located on the north side of the city. It hosts a wide range of artifacts and exhibits, with a focus on fossilexcavation and space exploration. Admission to the main building is 50 for a child's ticket. The laboratory next door is closed to the public, but return later to receive a valuable item from one of the scientists inside.

Pewter Gym
The Pewter Gym officially specializes in the Rocktype. Bulbasaur's Vine Whip and Squirtle's Water Gun can inflict serious damage on each of the four opposing Pokémon. Despite being a Fire type, Charmander can still hold its own with Metal Claw. Alternatively, a Mankey from Route 22 or a Butterfree from Viridian Forest can be a big help, as Rock Pokémon are vulnerable to Fighting-typemoves, and the Gym's Pokémon have a difficult time against special attacks like Confusion. Avoid bringing Flying and Electric Pokémon such as Pidgey or Pikachu.

Brock awards the player the Boulder Badge, which gives a slight Attack boost during battle, and allows the use of Flash in the field. He also hands over TM39 (Rock Tomb) as a prize.

With the Pewter Gym defeated, the next stop is Cerulean City to the east. Stock up on Potions and Poké Balls before leaving for Route 3. Upon leaving Pewter City, the player is stopped by one of Oak's aides. He delivers a package from Mom, which turns out to be a pair of Running Shoes. By holding the B Button, the player can travel faster than normal. While not as fast as the Bicycle, it is still faster than walking.

Route 3
Route 3 runs off to the east, ending at the east side of Route 4 and the entrance to Mt. Moon. There are more than a few Trainers to fight along the way, so it may be necessary to rest up in Pewter City before venturing into the cave.

Route 4 (west)
A Pokémon Center stands near the entrance to Mt. Moon. Inside is a shady man that offers to sell the player a Magikarp for 500. The fish can do nothing but Splash until level 15, but evolves into the much-stronger Gyarados at level 20. This offer allows the player to obtain the powerful sea snake earlier than normal, but Magikarp can soon be hooked for free with the right fishing rod.

Mt. Moon
Mt. Moon is a large cave set deep inside the mountains. There are many Trainers inside who are looking to battle. Many cave-dwelling Pokémon, like Zubat and Paras, can also be found here.