Route 25 is the peninsula east of Route 24, which is north of Cerulean City. The patch of tall grass contains the same species of wild Pokemon as those found on Route 24. A Hiker will be standing next to the only patch of tall grass on the route.
Defeat Nob to receive P560 and 3 Poke Balls. To the east are two Pokemon Trainers. It’s very important to remain near the southern side of the route so one of the Trainers walks downward and opens up a path to an item behind him.
The reward for defeating Coach Trainer Amala is P1600 and TM15 Seismic Toss. Seismic Toss does damage equal to the user’s level. The Machop in this battle will always inflict 16 HP of damage on your Pokemon. After the battle, grab the Lure to the south.
Now you can enter Bill’s sea cottage. Inside is a science experiment gone awry. Help turn Bill back to normal and he’ll reward you with two S.S. Anne Tickets. The S.S. Anne is located in Vermilion City.
With that side quest taken care of, head back to Cerulean City and take on the second Pokemon Gym. If you’ve already obtained the Cascade Badge, the house above the Gym will now open up!