Cleaveland Avenue is a long tubular passage in western Kentucky's Mammoth Cave, the longest cave on Earth. As of fall 2017, 412 miles of passages have been explored and mapped. Tubular passages are wider than they are tall, and are phreatic in origin - they form at or below the water table. In this case, the water table has long since lowered and the passage is currently dry. Local base level is the Green River. All water-bearing passages in the Mammoth Cave system drain toward the Green River, along which water emerges at springs.

Cleaveland Avenue is at Level C in the Mammoth Cave system. Level C passages started forming about 1.9 million years ago. A subterranean river used to flow through here. The photo is looking in the old downstream direction.

The rocks making up the walls and ceiling of Cleaveland Avenue are part of the Ste. Genevieve Limestone (upper Middle Mississippian).

This shot was taken next to a sharp bend in Cleaveland Avenue called the Snowball Dining Room. This was formerly an underground cafeteria that served meals to tourists. This was discontinued in the mid-2010s.

Snowball Dining Room occurs at the trough of a subtle syncline.