This explosive device will punch a hole in the ground, giving you a dark cavern to explore. There are even rumors of treasure hidden deep in the caves... but make sure you bring a World Lock. The blasted world is not locked when it's created, so lock it before somebody shows up! Remember: when using this, you are creating a NEW world by typing in a new name. You can't convert an existing world to a cave, that would be dangerous.
The Cave Blast is an unsplicable consumable which was added as part of the Spelunkorama! update on May 2, 2016. One can be purchased from the Store for 30,000 gems.