While most people are familiar with caves, karst may be a new term. “Karst topography” refers to a landscape dominated by springs, streams, sinkholes, and caves. The development of karst topography begins underground with a simple chemical reaction. As rainwater falls and soaks into the soil, it combines with carbon dioxide in the air and decaying vegetation to form a mild carbonic acid that slowly dissolves limestone bedrock, which underlies much of the Plateau. This process gradually enlarges small cracks and pores, allowing water to begin to pool. Over thousands of years, these small pores and cracks expand to become underground streams and caves. When underground caves collapse, sinkholes are formed. Springs form where groundwater is forced up and onto the surface through openings in the ground.

Karst formations are common near the escarpments and coves of the Plateau. One of the most obvious areas where karst topography can be seen is in the northern end of the Sequatchie Valley, home to Grassy Cove, the largest sinkhole in North America. Grassy Cove is drained entirely by underground streams. The valley's main stream, Grassy Cove Creek, flows northward across the cove then disappears into Mill Cave on the slopes of Brady Mountain. It winds its way through a series of caves before reemerging to form the headwaters of the Sequatchie River. Over geologic time, Grassy Cove will eventually become part of the Sequatchie Valley through continued dissolution of limestone and collapse of sinkholes.

In karst areas of the Plateau, a subsurface landscape exists that provides habitat to many rare species, some of which are exclusively found in a particular cave or sinkhole. The Cumberland Plateau has the highest concentration of caves and cave-dwelling invertebrate species in North America. A wide variety of cave-dwelling vertebrate species also live in Plateau caves, including two species of endangered bats.