Rock Tunnel is a two floor cave in eastern Kanto. It’s located in the middle of Route 10, and actually divides the route in two. To light up the cave, visit the eastern side of Route 2 after learning Chop Down. Professor Oak’s assistant will teach Light Up to your Partner Pokemon.
From the entrance, walk to the dead end in the east with the Repel. To the south is the path onward, but a Pokemon Trainer will challenge you to a battle before you can pass.
Defeat Winston to receive P1,104 and 3 Poke Balls. Follow the path all the way west until you reach a dead end with a Revive. Backtrack a short distance, then go north towards the next Pokemon Trainer. This Trainer will be standing next to a Dire Hit.
Defeat Eric to receive P672 and 3 Poke Balls. Next to Eric are 3 Great Balls. Pick up the items before taking the ladder to the west. A Pokemon Trainer will challenge you to a battle before you can take the ladder to the next floor.
Defeat Steve to receive P672 and 3 Poke Balls. South of this Trainer is a Super Potion, and to the north is the ladder leading back down and level.
This is the final area of Rock Tunnel. Near the ladder is a man who will give you free Poke Balls if you “run low.” If you have 0-9 Poke Balls in your bag, this man will give you 10 Poke Balls for free. It’s best to use this spot to learn how to catch Pokemon, build a catch combo, and even level up your team through capturing! Walk south to the next Trainers standing in the middle of the area.
Defeat Dana to receive P440 and 2 Great Balls. Travel to the far west end of the cave to find the last item of the cave: a Pearl. The exit to Route 10 is to the south.
Route 10 – South
The south half of route 10 is incredibly short. There are a few Trainers, but they can be avoided if you need to rush to the Pokemon Center in Lavender. Head east and jump the ledge to the south. However, if you want to battle everyone, you can go west to a Trainer near a ledge.
Defeat Clark to receive P1,000 and 3 Poke Balls. Just below Hiker Clark are 3 Great Balls. South of the Hiker is a Poke Maniac. You’ll have to jump the ledge to reach him from the west side. Alternatively, you can battle the other two Trainers to the east before the Poke Maniac to the south.