Sink of Hawkins River, Mammoth Cave, Edmondson County, KY

Fujichrome 100, OM-2S, 24mm lens, 1/60 second at f/2.8, T32 electronic flash, tripod.

"Into this small hole drains the entire volume of Hawkins River . I wanted to see what lay below, so I thought I'd better take a snapshot for posterity in case I couldn't get back up.  Very cold! I don't think anyone had ever been down there before..."