Inside this Caves Terrain is part of the interior of a cave. Bloons (and MOABS) enter from the bottom paths and the one top-left path, circle counterlockwise around the center and exit at the top-right corner, outside of the cave. The center space makes good use for towers with short range and area damage, such as Tack Shooters and Ice Monkeys. The single exit makes it suitable for a Spike Factory.
Upon completion, cave terrain tiles reward the player with City Cash and bloonstones. The amount of City Cash and Bloonstones given depends on the tile difficulty. This can range from 7 to 15 and approx. 700 to approx. 2500.