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 and one of the scientists inside will give you the Old Amber. His colleagues on Cinnabar Island can use the preserved DNA inside it to resurrect an ancient Aerodactyl.
PEWTER CITY POKéMON GYM LEADER: BROCK
The Rock Solid POKéMON Trainer!
For your Pikachu, the first Gym may be one of the toughest. The Pewter Gym officially specializes in the Rock type, though Brock's Pokémon also belong to the Ground type. Pikachu's electrical attacks are useless here, but it can still attack with physical moves like Quick Attack. Use a combo of Tail Whip and Quick Attack if you want to use Pikachu. Using Double Team, which it learns at level 15, will be especially helpful. Grass- and Water-type attacks would inflict massive damage, but Fighting moves are also effective. If you happened to catch a Mankey on Route 22, its Low Kick move can be a big help against Brock's Pokémon. If you prefer to use either Nidoran♀ or Nidoran♂ for this fight, level it up to level 12 when it learns Double Kick which should take Brock out.
A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here.
The Magikarp Salesman
A Poké Center stands near the entrance to Mt. Moon. Inside is a shady man that will offer to sell you a Magikarp for 500. The fish can do nothing but Splash until level 15, but evolves into the powerful Gyarados at level 20. If you have the money to spare, you can have a strong Water-type Pokémon that much sooner, but you can soon hook one for free with the right fishing rod.
Collect TM12 (Water Gun) and the Potion to the left, then follow the tunnel around and climb down the nearest ladder.
The presence of a Team Rocket grunt means that the criminal gang is up to no good here. Grab the HP Up from the ledge and climb back to the first floor.
To the south are two more Trainers. There are also three items lying around, including a Potion, Rare Candy, and an Escape Rope. A Rare Candy raises a Pokémon's level by one, and an Escape Rope warps you to the cave entrance if you need to heal up. Go north and climb down the next ladder.
Beat up the second Rocket grunt, then pick up TM01 (Mega Punch) 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.
Follow the winding tunnel to the northwest, where a Super Nerd claims both fossils lying here as his own. Defeat him, and he lets you take your pick of the two. Like 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. Head for the final ladder with your new fossil in tow, and a pair of Rocket grunts appear and attacks.