Dark Cave (Japanese: くらやみのほらあな Dark Cave) is a single-level cave located in eastern Johto. The northernmost point in the cave is at the entrance leading to and from Route 45 just south of Blackthorn City. The path of the cave makes a 180-degree turn to the right before proceeding south for a short distance to the first of two underground ponds in the cave. Trainers can Surf directly south to reach a Revive, to the southwest then to the north to reach a man who hands out the Black Glasses, or to the southwest to make landfall near TM13 (Snore). West of TM13, the path from the Black Glasses man merges with the TM13 path as it turns south and enters the southern portion of Dark Cave.
Immediately after emerging from the north half, the path comes to the second of two ponds. Trainers can Surf to the west from this point to snag a Potion and reach Route 31, or, if a Pokémon knows Rock Smash, they can also Surf to the south and dispose of a series of rocks as they head eastward toward a Hyper Potion. Near the item, the path of the cave turns south, passing a Full Heal before reaching its southernmost point at Route 46.