Underground Moon Caverns

The Underground Moon Caverns, known colloquially as the Moon Cave, is one of the largest sub-worlds in the game and can be found in the Moon Kingdom. The level, which contains a total of five Power Moons and 18 regional coins, is a gauntlet of many different game mechanics and capture types and culminates in a rematch against Madame Broode. Entering and traversing the level is intended to be a requirement to beat the game, but the famous Moon Cave Skip speedrun trick allows the level to be skipped entirely from the outside, which can save up to two minutes or more in some speedruns.

Trivia

• It is possible to reach the top of the large rock wall at the very end of the sub-world. This is done by jumping up to and slipping through a small gap in the collision, which allows the player to reach an out-of-bounds area up inside the wall. From there it is possible to wall jump up some unused collision to reach the top.
  • Climbing up high enough causes the textures on the pillar to flicker. If the player uses Assist Mode to place their safe spot on top of the pillar and then jumps off into the void, the textures will briefly flicker much more aggressively after the bubble returns Mario to the top of the pillar.
• The large rock wall at the beginning of the sub-area has no collision on top, so it cannot ever be possible to stand on.
• Below the Madame Broode arena, there are various vertical holes that can be wall jumped up if the player is skilled enough to jump into them. Additionally, one of these holes even has moon rock formations jutting out that can be stood on, which can be used to reach an even farther hole.
• On the central island with the Banzai Bills, there are three tall rock pillars that seem to be too tall to reach the top of. One of them is possible to climb onto in single-player mode using a very precise vertical trickjump, or using an easier variant of the jump in two-player mode. Of the other two pillars, one can be climbed onto directly using an extremely precise two-player vertical trickjump, and from the top it is possible to perform another trickjump to reach the third and final pillar.
• It's possible to get a Parabones capture out of the pit that they are originally found in by using a slightly sloped wall on the side of one of the nearby vertical pillars to raise its elevation. This can be done either by flying against the sloped wall as the Parabones while repeatedly pressing X or Y with specific timing, or by hovering on the opposite side in order to bait another Parabones up the slope.