Lavender Town is still a small town, though it experienced a big change during the last three years as Pokémon Tower was converted into the region's new Radio Tower.
Kanto Radio Tower
The tower security has been on alert ever since Johto's Radio Tower was taken over by Team Rocket, so visitors are restricted to the first floor. Accessing Kanto's radio programs requires an EXPN Card for the Pokégear. However, an incident at the Kanto Power Plant has disrupted the tower's energy supply, so you must restore power before you can obtain the EXPN Card.
House of Memories
The House of Memories was built to accommodate the departed Pokémon from the former Pokémon Tower site. There are several graves on the ground floor, and many more located in underground chambers that are off-limits to all but the caretaker, Mr. Fuji.
The Name Rater lives in the southeast house, and allows Trainers to rename any of their Pokémon. However, he cannot rename a Pokémon obtained in a trade.
Climb onto the platform and take the eastern stairs down, then east to the rock formations. Head to the southern-most rock formation to obtain an X Defend, then head north to collect TM56 (Fling). Return to the platform and take the western stairs, then immediately north, to find an Elixir. Head southwest and take the ladder to the basement.
Go northeast to pass by several paths running down the wall. Head northwest from here and climb the ladder.
Head east, then turn to the northwest. Inspect the southern part of the platform for a hidden X Accuracy, then pass over the northern part to reach the northwest ladder.
Grab the Revive to the east, then take the next pair of stairways eastward. The next stairway leads to a lower area with a PP Up. Continue on to the southeast corner and use Rock Smash to find a hidden Max Potion. Climb the ladder back to 1F.
Follow the path northeastward to the exit.
Route 10 (north)
Outside the tunnel's northern exit is a conveniently-placed Pokémon Center. Chat up the patrons inside to learn that the Kanto Power Plant's manager is looking for a strong Trainer to recover a stolen piece of equipment. Head up north to the canal, then swim southward to reach the building.
The old, abandoned Kanto Power Plant was recently renovated in order to power the region more efficiently. However, a thief has stolen an essential part of the new generator, forcing it offline. As you turn to leave, the police officer is alerted to a shady character that has been seen loitering around Cerulean City, and asks you to check it out. Surf back northward and head west to reach the city.