A system of tunnels and caves in the side of some mountain. Some tunnels lead underground to larger, darker caves. Most of these caves haven't been explored much, as it's a very high drop.
Plenty of bats and rocks to be found in here. There's also some pools of water from small waterfalls that are barely more than a trickle.
A few wild animals have made their home in some of the caves, but they usually don't do much besides sleep.
There's a large cave where Waddle Dees spend all their time mining the stone, looking for gold to take back to King Dedede. They still haven't found gold. They're not allowed to go home until they do.