Krematoa

Krematoa is the secret area in Donkey Kong Country 3: Dixie Kong's Double Trouble! for the SNES, similar to the Lost World from Donkey Kong Country 2. It emerges from under the ocean as an underground volcano on the overworld map after the player travels counterclockwise around a circle of four rocks in the center of the map three times. 
 
The neutral starting point is the bomb shelter of the bear Boomer, who provides a detonation blast for every 15 Bonus Coins provided by Dixie and Kiddie Kong. There are five levels in Krematoa, each requiring a detonation to uncover, thus the player must find all 75 Bonus Coins in the game to unlock all levels. After completing each level, the player earns a "cog," which can then be given to Boomer to be placed on his crank machine. After all five cogs have been collected, a submarine emerges from the center lake, where the game's true final boss battle takes place. 
 
There is also a Wrinkly's Save Cave to the right of Boomer's bomb shelter.