The Underground Maze is the Zelda series-themed level found in Adventure Mode in Super Smash Bros. Melee. It is designed like a labyrinth, with branching pathways, and also has Zelda-themed enemies, such as ReDeads, Like Likes, and Octoroks.
There are six open spaces in the dungeon, one of which contains a pedestal with the Triforce, which is the stage's exit. The other five contain a pedestal with a Master Sword, which will summon Link to fight the player. If all five Links are defeated before the Triforce is reached, the player will receive the Link Master bonus. The location of the Triforce is random.
The Underground Maze is available through hacking, though entering one of the open areas may cause unwanted results, such as the game crashing or the match ending.