In the dank depths of Ellison’s Cave, you can find two of the deepest freefall pits in mainland US: Fantastic Pit, which plunges vertically for 179 meters (586 feet); and Incredible Pit, an equally dizzying 134 meters (440 feet) deep.
Ellison’s Cave is located on Pigeon Mountain among the Appalachian Plateaus of Northwest Georgia. The entire cave system is around 19 kilometers (12 miles) long and 324 meters (1,063 feet) deep, making it the 12th deepest cave in the country.
Its vertical pits, just like most caves, are formed via erosion by water over thousands upon thousands of years. Rainwater and other flowing groundwater can pick up carbon dioxide from the air, causing it to become acidic enough to dissolve the limestone. Simply due to gravity, the water flows downwards, carving out channels over very long periods of time.
Ellison’s Cave is also situated on an active fault within Earth’s crust. Over time, the slightly acidic water has dissolved the rock along these deep fractures, slowly expanding them into vertical shafts.
A view of the Fantastic Pit in Ellison’s Cave looking up towards the surface.
Cavers and climbers have scaled much of Ellison’s Cave, although it’s recommended only for the most experienced adventurers due to its dangerous and extreme conditions.
Indeed, the cave has been known to take lives. Back in 2011, two college students from the University of Florida died while exploring Ellison’s Cave. One of the climbers used a rope to drop into a pit to retrieve a bag but became tangled in his ropes while a cold waterfall poured on top of him. His friend attempted to help him but also got stuck. Both men died of hypothermia.
For the deepest vertical pit cave in the world, head to Slovenia near the border with Italy. Vrtiglavica, found in the Kanin Mountains of the Western Julian Alps, has a vertical pitch that plunges for 603 meters (1,978 feet). Its name aptly means “vertigo” in Slovenian.
First discovered in the summer of 1996, a joint Slovenian–Italian expedition managed to reach the bottom of the pit just a few months later on October 12, 1996.
Still, Vrtiglavica is not the deepest abyss in the world. That honor goes to a sinkhole in China called Xiaozhai Tiankeng, or the Xiaozhai Heavenly Pit, which sinks between 511 and 662 meters (1,667-2,172 feet) into the Earth.
Source Link: Fantastic Pit: Deepest Vertical Pit Cave In Mainland US Plunges 179 Meters