Ruby Falls is the world's tallest and deepest underground waterfall open to the public. 
Not like Portland it never rains at weather proof Ruby Falls.
Over 80 years ago... A young man named Leo Lambert became fascinated by the idea of reopening the Look Mountain Cave to the public. This cave had been home, hideout and curiosity to American Indians, Out laws, Civil War soldiers and even President Andrew Jackson before being sealed of during the construction of the railroad at the turn of the century. Determined to rediscover the Cave, Lambert proceeded to drill an elevator shaft down towards the LookOut Mountain Cave. During the excavation of the 420feet of elevator shaft, a small opening was discovered at the 260 feet level. Leo Lambert and group of fellow explorers entered the opening, spending most of the next 17 hours crawling on their hands and nees. As they pushed deeper into the Cave, they began hear the sounds of water flowing in the distance.
They were awestruck by the magnificent beauty of the waterfall they had discovered, later naming the falls in honor of his wife, Ruby. Lambert continued on until he reopened the original lookout Moutain Cave and in 1928 Lambert opened his castle door to the public.
No trip to the Ruby Falls would be complete without visiting the lookout mountain tower. Modeled after 15th century Irish castle and was constructed by the lime stone recliamed from the elevator excavations in the 1920's.
Geology
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 eats away at 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.
Ruby Falls Cave features many of the more well-known types of cave formations (or speleothems) including stalactites and stalagmites, columns, drapery, and flowstone.
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.
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.
"Ruby Falls" is also the title of a song by the indie rock band Guster, which appears on their 2006 album Ganging Up on the Sun.
Johnny Cash once recorded "See Ruby Fall", a play on words of Ruby Falls.
The hard rock band Mastodon filmed the performance footage of the music video for their song "Colony of Birchmen" from the album Blood Mountain inside Ruby Falls. The waterfall itself can be seen in the background.
Ray Stevens performed a song entitled "Ruby Falls".
In South Park (season 3) episode, "The Red Badge of Gayness," Cartmen writes of Kenny's death at "the Battle of Ruby Falls Funland."
A popular high school rock band in Columbia, Missouri took on the name Ruby Falls in the fall of 2009. Current members include Carter Datz, Keegan Ruebling, Andrew Cox and Jacob Keener all of which go to Hickman High School in Columbia.
Tourism and Advertising
Ruby Falls and the larger Lookout Mountain Caverns complex have been designated a National Historic Landmark. It is often associated with the nearby Rock City attraction, which lies atop Lookout Mountain.
History
Ruby Falls Cave, unlike Lookout Mountain Cave, had no natural openings and was not able to be entered until the 20th Century; it therefore does not have the various artifacts which are often associated with caves in the southeastern United States. In 1905 the natural entrance to Lookout Mountain Cave was closed during the construction of a railway tunnel. In the 1920s a chemist and cave enthusiast named Leo Lambert thought that he could re-open the cave as a tourist attraction, and formed a company to do so. He planned to make an opening further up the mountain than the original opening and transport tourists to the cave via an elevator. For this purpose, his company purchased land on the side of Lookout Mountain above Lookout Mountain Cave and in 1928 began to drill through the limestone. In doing so, they discovered a small passageway about 18 inches high and four feet wide. Exploring this opening, Lambert discovered the formerly hidden Ruby Falls Cave and its waterfall.On his next trip to visit the cave, Lambert took his wife Ruby, and told her that he would name the falls after her.
In 1954, the pathway around the basin was cut in order to allow tourists a better view of the falls.This began the tour-related quip regarding not drinking the falls' water. 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.
In 1975, the secondary exit from the falls to the base of the mountain was cut. This was to comply with recreation regulations in Tennessee. The secondary exit is used in the event that the main shaft elevator fails.
In April, 2007, the National Speleological Society (NSS) published "Caves of Chattanooga" by Larry E. Matthews. Chapter 3, "Ruby Falls Cave", covers the history of Ruby Falls Cave from its discovery in 1928 through 2007 (includes 23 illustrations). Chapter 1, "Lookout Mountain Cave", covers the cave Leo Lambert was drilling for when he accidentally discovered Ruby Falls Cave.
Not like Portland it never rains at weather proof Ruby Falls.
Over 80 years ago... A young man named Leo Lambert became fascinated by the idea of reopening the Look Mountain Cave to the public. This cave had been home, hideout and curiosity to American Indians, Out laws, Civil War soldiers and even President Andrew Jackson before being sealed of during the construction of the railroad at the turn of the century. Determined to rediscover the Cave, Lambert proceeded to drill an elevator shaft down towards the LookOut Mountain Cave. During the excavation of the 420feet of elevator shaft, a small opening was discovered at the 260 feet level. Leo Lambert and group of fellow explorers entered the opening, spending most of the next 17 hours crawling on their hands and nees. As they pushed deeper into the Cave, they began hear the sounds of water flowing in the distance. 
No trip to the Ruby Falls would be complete without visiting the lookout mountain tower. Modeled after 15th century Irish castle and was constructed by the lime stone recliamed from the elevator excavations in the 1920's.
Geology
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 eats away at 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.
Ruby Falls Cave features many of the more well-known types of cave formations (or speleothems) including stalactites and stalagmites, columns, drapery, and flowstone.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.
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.
Popular culture references
An all-female American indie rock band called Ruby Falls was active during the 1990s. Based in New York City, the group was founded in 1992 and disbanded in 2000.
"Ruby Falls" is also the title of a song by the indie rock band Guster, which appears on their 2006 album Ganging Up on the Sun.
Johnny Cash once recorded "See Ruby Fall", a play on words of Ruby Falls.The hard rock band Mastodon filmed the performance footage of the music video for their song "Colony of Birchmen" from the album Blood Mountain inside Ruby Falls. The waterfall itself can be seen in the background.
Ray Stevens performed a song entitled "Ruby Falls".
In South Park (season 3) episode, "The Red Badge of Gayness," Cartmen writes of Kenny's death at "the Battle of Ruby Falls Funland."
A popular high school rock band in Columbia, Missouri took on the name Ruby Falls in the fall of 2009. Current members include Carter Datz, Keegan Ruebling, Andrew Cox and Jacob Keener all of which go to Hickman High School in Columbia.
Tourism and Advertising
Lambert decided to open both caves to the public, although Lookout Mountain Cave was closed in 1935 since it was not very popular with tourists, who were much more impressed with the upper cave. Public tours began in 1930. Electric lights were installed in the cave, making it one of the first commercial caves to be so outfitted.Motorists travelling on I-75 in the 70's were subjected to dozens - maybe hundreds - of billboards along their route with the words "SEE RUBY FALLS" beginning hundreds of miles north and south of the falls itself. Ruby Falls remains a staple of Chattanooga tourism, operating daily. Ruby Falls is owned by the Steiner family of Chattanooga, Tennessee.
History
Ruby Falls Cave, unlike Lookout Mountain Cave, had no natural openings and was not able to be entered until the 20th Century; it therefore does not have the various artifacts which are often associated with caves in the southeastern United States. In 1905 the natural entrance to Lookout Mountain Cave was closed during the construction of a railway tunnel. In the 1920s a chemist and cave enthusiast named Leo Lambert thought that he could re-open the cave as a tourist attraction, and formed a company to do so. He planned to make an opening further up the mountain than the original opening and transport tourists to the cave via an elevator. For this purpose, his company purchased land on the side of Lookout Mountain above Lookout Mountain Cave and in 1928 began to drill through the limestone. In doing so, they discovered a small passageway about 18 inches high and four feet wide. Exploring this opening, Lambert discovered the formerly hidden Ruby Falls Cave and its waterfall.On his next trip to visit the cave, Lambert took his wife Ruby, and told her that he would name the falls after her.
In 1954, the pathway around the basin was cut in order to allow tourists a better view of the falls.This began the tour-related quip regarding not drinking the falls' water. 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.
In 1975, the secondary exit from the falls to the base of the mountain was cut. This was to comply with recreation regulations in Tennessee. The secondary exit is used in the event that the main shaft elevator fails.
In April, 2007, the National Speleological Society (NSS) published "Caves of Chattanooga" by Larry E. Matthews. Chapter 3, "Ruby Falls Cave", covers the history of Ruby Falls Cave from its discovery in 1928 through 2007 (includes 23 illustrations). Chapter 1, "Lookout Mountain Cave", covers the cave Leo Lambert was drilling for when he accidentally discovered Ruby Falls Cave. 
