Course No.23 is the fourth course of Stove Canyon in Wario Land: Super Mario Land 3. The main mechanic of this level is flat, Mine Cart-like platforms with wheels that carry Wario along the tracks that make up most of the level. Aside from the checkpoint room, the entire level takes place in one large area with many lava pits scattered throughout. Two exits can be found at the end of the level.
Wario finds the first cart next to a block containing a Garlic Pot. While riding the cart, Wario must jump over a Demon Bat and, before the cart falls into the lava, up to a pillar, then jump across two more pillars while avoiding two more Demon Bats towards another cart. Wario then rides along three tracks leading down; when the cart reaches a wide lava pit, Wario must make a farther jump towards another cart where a Demon Bat awaits above, then repeat the same process for another one, until he reaches a large platform with another Garlic Pot block. The cart here transports Wario along a downward stairway-like track to another platform past the lava pit at the end with a Spring-Up that bounces him up to an even higher platform. The door to the checkpoint is found here.
After activating the checkpoint, Wario can climb down to the tracks using the ladder on the right. Once Wario starts riding the cart located under the door, he can jump up to a high platform and walk to the right to collect a row of coins, then drop back down and continue heading right. Wario then finds two blocks containing a Garlic Pot and a heart, followed by three pillars Wario must jump along while avoiding the nearby Demon Bats to reach the next cart, which travels along a short track before falling into the lava, forcing Wario to jump to another cart. As this cart travels along the divided tracks, Wario can again take an alternative route across the high platforms while collecting more coins. After Wario jumps over the lava pit and up the stairs, he must take another shortlived cart at the top to make a jump to a ledge on the other side, where the goal door is found.
While on the last cart in the level, Wario must stay on it until just before it lands in the lava, at which point he must jump to the low platform on the right underneath the platform with the regular exit, where a Spring-Up can be found. Wario can then use it to bounce up to a high platform located off-screen, where he finds another block that bounces him up to the secret goal door leading to Course No.24.