From the Super Mario Wiki, the Mario encyclopedia
Fiery Volcano is a level in DK: Jungle Climber, and it is the fourth one of Chill 'n' Char Island. Taking place in a Volcano, Donkey Kong has to climb through the volcano in order to avoid rising lava. In some parts, there are holes pouring out lava, and the player must throw rocks into them in order to get to certain areas. There are also large wheels with pegs on them that Donkey Kong must use in order to progress. Enemies here only include Mini-Neckies. To get the DK Coin, the player needs to throw two pebbles into the holes with lava pouring out of them so that it'll start sinking, revealing the DK Coin in the new passage.