Take a hike into the cool confines of an underground cave system on Middle Caicos Island. Conch Bar Caves is the largest nonsubmerged system in the region, featuring a type of cave that is created by the karst process in which rain water slowly erodes subterranean channels through limestone. Exploring the interior will reveal chambers with tidal pools, rock formations, and four species of bats. Some instances of graffiti within the caves are over a century old, left by guano miners during the late 1800s and early 1900s. Visitors must hire a local guide to enter the caves.