<P> The cave which houses Ruby Falls was formed with the formation of Lookout Mountain . About 200 to 240 million years ago (in the Carboniferous Period, at the end of the Paleozoic Era) the eastern Tennessee area was covered with a shallow sea, the sediments of which eventually formed limestone rock . About 200 million years ago, this area was uplifted and subsequent erosion has created the current topography . The limestone in which the cave is formed is still relatively horizontal, just as it was deposited when it was below sea level . The Lookout Mountain Caverns, which includes Ruby Falls Cave, is a limestone cave . These caves occur when slightly acidic groundwater enters subterranean streams and slowly dissolves the relatively soluble limestone, causing narrow cracks to widen into passages and caves in a process called chemical weathering . The stream which makes up the Falls entered the cave sometime after its formation . </P> <P> Ruby Falls Cave features many of the more well - known types of cave formations (or speleothems) including stalactites and stalagmites, columns, drapery, and flowstone . </P> <P> The Falls are located at the end of the main passage of Ruby Falls Cave, in a large vertical shaft . The stream, 1120 feet underground, is fed both by rainwater and natural springs . It collects in a pool in the cave floor and then continues through the mountain until finally joining the Tennessee River at the base of Lookout Mountain . </P> <P> While Ruby Falls Cave combines with Lookout Mountain Cave to form the Lookout Mountain Caverns, the two caves were not actually connected by any passage . Ruby Falls Cave is the upper of the two and contains a variety of geological formations and curiosities which Lookout Mountain Cave does not have . </P>

Where does the water from ruby falls come from