This is an accepted version of this page Ruby Falls is a series of underground cascading waterfalls totaling 90 feet (27 m) in Lookout Mountain, near Chattanooga, Tennessee, in the United States.

[2][3] About 300 to 360 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.

[4] About 200 million years ago, this area was uplifted, forming Lookout Mountain and nearby ridges.

This process, called chemical weathering,[5][6] caused various caves to form inside Lookout Mountain.

Though pure and thus safe to drink, it has large concentrations of magnesium from the strata of the mountain, which makes it a natural laxative.

This secondary exit was used for the popular Ruby Falls Haunted Cavern until 2017 when the event was renamed Dread Hollow and was moved to a new location.

[12][13] In April 2007, the National Speleological Society (NSS) published "Caves of Chattanooga"[14] by Larry E. Matthews.

Ruby Falls and the larger Lookout Mountain Caverns complex have been designated a National Historic Landmark.

Johnny Cash and Roy Orbison co-wrote a song with the title "See Ruby Fall" in the mid to late 1960s, a reference to the barn roof advertising slogan "See Ruby Falls" ubiquitous throughout the southern United States in the mid 20th Century.