Crooked Cavern

Crooked Cavern, or Acorn Plains-2, is the second course of Acorn Plains, and subsequently, the second course of New Super Luigi U. It's unlocked by completing Waddlewing Warning!, and its own completion unlocks Flame-Gear Tower and the first Toad House.

Layout
The first area is a small overworld field where three pipes are found, the left and right ones are red and contain Piranha Plants, while the middle one is green and leads to the cave. This cave is made of many moving crystals and red pipes with Piranha Plants. At the end, there is a Warp Pipe above a pit to the third and final area.

Star Coins

 * Star Coin 1: At the beginning in a secret area left of the left side Piranha Plant.
 * Star Coin 2: Under some Brick Blocks. The player must throw the nearby Koopa Troopa at these blocks in order to collect it.
 * Star Coin 3: Directly above the secret exit, the third Star Coin is at the end of a coin trail that comes after the first exit pipe.

Secret Exit
Right after the third Star Coin, Ground Pound the spot where the Arrow Sign is and follow the signs to the secret exit. The secret exit leads to Cheep Chomp Chase.

Luigi sighting

 * Before the normal exit, an 8-bit Luigi can be found under the stairs of blocks.

Enemies

 * Koopa Troopas
 * Piranha Plants