Caves Terrain

 is a special, but unmarked terrain in Bloons Monkey City (similar to Volcano Terrain). There are five cave terrain tiles on every map and it is believed this could be linked to a Portal Artifact. Gameplay is the same as a normal Mountain Terrain. This type of terrain favors Ice Monkeys but restricts Monkey Aces, Banana Farms, Dartling Guns and Heli Pilots, unless when played in Replay Tracks on Flash. On Flash's Replay Tracks, Monkey Engineers are favored while Monkey Aces and Mortar Monkeys are restricted.

Description
Inside the Caves Terrain is part of the interior of a cave. Bloons enter from the bottom paths and the one top-left path, circle counterclockwise 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.

Tips

 * Placing a Spike Factory near the exit may help pop those bloons that break through your defenses.

Rewards
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.

Trivia

 * Cave terrain tiles show up as mountain terrain tiles on the game map.
 * However, in the Maps & Towers menu, they are labelled as Caves Terrain.
 * After the update that included replayable special missions in My Tracks, the Caves Terrain no longer appears in the Mountain Terrain section of My Tracks, not even after completing it. However, it may be reencountered in Contested Territory events.