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's Parcel is delivered to him), so stock up at the Poké Mart before challenging the Gym.
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 fossil excavation 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 CITY POKéMON GYM LEADER: BROCK
The Rock Solid POKéMON TRAINER!
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 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.
Trainers with a Vs. Seeker by their names, when alerted for a rematch using the item, may use higher-level Pokémon.
Route 4 (west)
Mt. Moon, 1F
Mt. Moon, B1F
Mt. Moon, B2F
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.
The presence of a Team Rocket Grunt means that the criminal gang is up to no good here. Grab the Star Piece from the platform and take the ladder back to the first floor.
To the south are two more Trainers. There are also three items lying around, including a Potion, a Rare Candy, and an Escape Rope. Go north and climb down the next ladder.
Beat up the second Rocket Grunt, then pick up TM46 (Thief) on the platform. Check the boulder for a hidden Ether and return to the main floor.
Continue along the tunnel to the northwest corner of the cave. Grab the Moon Stone in the corner and take the ladder to the basement.
B2F (outer area)
Follow the winding tunnel to the northwest, where Super Nerd Miguel claims both fossils lying here as his own. Defeat him, and he lets the player pick one of the two. Like with the Old Amber, the scientists on Cinnabar Island can resurrect a prehistoric Pokémon from each fossil. The Helix Fossil will become an Omanyte, while the Dome Fossil will become a Kabuto; both are Rock/Water Pokémon. Climb the final ladder to reach the exit.
Route 4 (east)
Route 4 is a one-way path that leads down from the mountains. Pick up TM05 (Roar) and the hidden Great Ball before jumping the ledge outside Cerulean City. A pair of Black Belts can be found training on the western hill. These men are Move Tutors, and each wishes to pass on the knowledge of a certain move. The man on the left teaches Mega Punch, while the man on the right teaches Mega Kick. Like the other Move Tutors, these moves can be taught only once.