Pokémon HeartGold and SoulSilver/Dark Cave

There isn't much you can do in the Dark Cave at first. You will only have access to one room right now, but that's all you need to get a Zubat, which isn't great on it's own but with a little love and leveling, you can get a very strong Crobat fast. You need to teach a Pokémon Flash to light up the cave. Then, on the Route 31 side, there will be two boulders in your way that require Rock Smash to go on.

Here are the following Field Moves you need:Flash(TM70),Rock Smash,Strength,and Surf. Rock Tunnel leads to the following routes:#45 (to Blackthorn City),#31 (to Violet City),and #46 (to New Bark Town). Items : Potion, Dire Hit, Full Heal, Hyper Potion, Black Glasses, Revive, and TM False Swipe. Step 1: Light the Way With Flash