Olympus C3040 digital camera, 1/125 second at f/2.3, built-in flash, handheld.
"Beyond the tight canyon passages, something amazing happens: the passage widens slightly and the floor disappears. Here is the breech of Stupendous Pit, which drops over 200 feet into the Rumble Room. A tremendous amount of air rises up from below, often chilling those who must await cavers coming up from the pit. In this image Curtis Beasley reaches the top of the room. Curiously, this rock balcony and surrounding "walls" are composed of hundreds of tons of loose rock."