Ruby Falls: Discovering Tennessee's Underground Waterfall
Located in Chattanooga, Tennessee, Ruby Falls overs a cave experience unlike any other. Not only will you get to see magnificent cave formations but you will get to witness the tallest and deepest underground waterfall open to the public in the United States! Keep reading to learn all about the accidental discovery of the cave, how it became what is today, and how you can experience the wonder for yourself.
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What is Ruby Falls?
Located 1,120 ft beneath the surface of Lookout Mountain in Chattanooga, Tennessee, at 85 ft tall, Ruby Falls is the tallest and deepest underground waterfalls open to the public in the US. The waterfall is red by rainwater that percolates from the surface down through the mountain's limestone into a vertical shaft called a dome-pit. The water collects in a pool at the base of the falls and flows through the mountain to ultimately resurface as a natural spring near the Tennessee River. A water-recycling system as been put into place within the cave t manage the natural runoff, prevent flooding, and reserve groundwater resources.
The History and Discovery of Ruby Falls
Did you know Ruby Falls was discovered by accident?!
Lookout Mountain Cave had been well known for centuries. It was first used by Native people and was later used as a hospital and shelter during the Civil War. Later, it would be sed as a legendary hideout for moonshine runners and thieves! When Leo Lambert learned about the history and folklore of Lookout Mountain Cave, he set out on what would be a decade-long question to open the cave to the public. After securing $250,000 from investors to fund his new business in 1928, Lambert began building an elevator shaft down into the cave. Excavated limestone would save to make what was intended to be "the most beautiful cave entrance in the world!"
The progress of the cave excavation was slow. Even with crews working around the clock, they were only able to remove 5 ft of limestone every 24 hours! After several weeks, crews hit a void in the rock and felt wind gushing out. Lambert and a small group of crawled through the dark chasm to investigate. They returned 17 hours later having discovered there were flowing underground streams, incredible geological formations, and a plunging underground waterfall. Lambert named the waterfall Ruby Falls in honor of his wife.
In 1929, the cave entrance, a castle, was completed and tours of Look Out Mountain Cave began. 6 months later, Ruby Falls would start welcoming tourists as well. This however, was a tough time to be bringing in customers as Chattanooga along with the rest of the national was struggling with the effects of the Great Depression. Since travel was considered a luxury during this time, social offerings at the Castle along side heavily discounted tickets helped keep Ruby Falls operational during time.
How was Ruby Falls Cave Formed?
The Geology of Lookout Mountain
The cave formed within a layer of limestone, a type of sedimentary rock that developed from material deposited in ancient seas hundreds of millions of years ago. Over time, geological forces shaped the region, creating the mountain and the layers of rock that now surround the cave.
But the mountain itself is only part of the story. Water played a major role in creating the cave visitors explore today. As rainwater moves through the soil, it absorbs carbon dioxide and becomes slightly acidic. When this water seeps into cracks and fractures in limestone, it slowly dissolves the rock, gradually widening small openings into passageways and chambers. This process, which takes place over thousands to millions of years, is how many limestone caves form.
At Ruby Falls, the natural cracks and layers in the rock also help direct underground water through the mountain. Eventually, these pathways lead to the dramatic underground waterfall that made the cave famous. It's a reminder that some of nature's most impressive features are created through incredibly slow processes happening out of sight beneath our feet.
Cave Formations to Look For
The waterfall might be the main attraction, but take time to look around as you make your way through the cave. The walls and ceilings feature geological formations that developed as mineral-rich water moved through the limestone over long periods of time.
Some of the most recognizable cave formations include:
Stalactites: Mineral deposits that hang down from the ceiling as water drips and leaves behind tiny amounts of calcium carbonate.
Stalagmites: Formations that grow upward from the cave floor as mineral-rich water drips onto the ground below.
Flowstone: Smooth, layered deposits that form when mineral-rich water flows over cave walls or floors, sometimes resembling a frozen waterfall.
Drapery formations: Thin, curtain-like sheets of mineral deposits that develop where water travels along sloping rock surfaces.
These formations grow slowly, often taking thousands of years to develop noticeable features. Their shapes and sizes depend on factors such as water flow, mineral content, and the structure of the surrounding rock.
You may also notice fossils preserved in the limestone walls. These provide clues about the ancient marine environments in which the rock originally formed. Ruby Falls' specialty Geology Tour explores these features in greater detail, offering a closer look at the science behind the cave's formations.
One important thing to remember is that cave formations are delicate. Even seemingly solid deposits can be damaged by contact, so it's best to admire them without touching them.
Where Does the Waterfall Come From?
Of course, the big question is where all that water comes from. Ruby Falls is fed by underground water that travels through the surrounding rock and cave system. Rainfall and conditions across the local watershed influence how much water reaches the falls, which means its flow can change over time.
As water moves through cracks and underground passages in Lookout Mountain, the geology directs it toward vertical openings within the cave. At Ruby Falls, the water plunges into a large cavern, creating the underground waterfall visitors come to see.
What makes the experience especially fascinating is that the waterfall is hidden deep inside the mountain, far from the typical setting where you'd expect to find a waterfall. Rather than hiking to a waterfall along a mountain trail, visitors descend into the cave and follow a guided path through the rock to reach it.
The waterfall's natural surroundings are part of what makes Ruby Falls so memorable. The towering limestone walls, the sound of falling water, and the sheer scale of the cavern offer a glimpse into the geological processes that have shaped Lookout Mountain over an immense span of time.
Planning Your Visit to Ruby Falls
Location and Directions
Located on Look Out Mountain, getting to Ruby Falls requires driving up winding switchbacks. Don't worry though, this road can be managed by any type of vehicle although it might be a little harder for large RVs or trailers. When you arrive, there is a fairly large, free parking lot. Keep an eye out for pedestrians walking along the road!
Address: 1720 South Scenic Highway, Chattanooga, Tennessee.
Tickets and Tour Reservations
With several different types of tours, Ruby Falls offers something for every type of traveler. Whether you're looking for the classic experience, want to learn more about the history of the area, or want to see what it was like for the original explorers wandering the cave with only a lantern, you'll find something your enjoy - and maybe have a reason to come back and go on a different tour!
Ruby Falls current advises visitors to book in advance as tour time slots can sell out and walk-up tickets are not available. When booking tickets, you'll select wich tour type you want to do and then select an available time slot from there. Tower entry is included in the ticket so be sure to have a look at the views from the top before or after your tour!
*note: prices and tour offerings are as of October 2026, check Ruby Falls website for current offerings
Cave Walk to the Waterfall
Adult - $29.95
Child (ages 4-12) - $19.95
Senior (65+, ID required) - $28.95
Child, age three and younger - Free
Offered Daily
Guided, express walk through the cave to the waterfall, appropriate for all ages.
Participants should be comfortable walking, standing, and keeping pace with the group for up to 90 minutes.
Lantern Tour
$42.95
Friday nights, after-hours
Explore the cave and waterfall on a specialty tour, illuminated only by the light of hand-held lanterns!
For ages 10 and up
Participants should be comfortable walking, standing, and keeping pace with the group for up to 120 minutes in a low light environment.
Junior Caver Tour
Adult - $29.95
Child - $29.95
Offered Select Days
Curiosity leads the way on the new Jr. Caver Tour, the ultimate interactive guided cave adventure for families visiting with children!
Participants should be comfortable walking and standing for up to 120 minutes and keeping pace with the group.
History Tour
$40.95
Offered on Select Days
Specialty tour with early-access
Appropriate for guests age 12 and older
Participants should be comfortable walking and standing for up to 120 minutes and keeping pace with the group.
Gentle Walking Tour
$40.95
Offered on Select Days
Gently paced specialty tour with early-access, offered select days
Children younger than 12 years old are not permitted on Gentle Walking Tours
Participants should be comfortable standing, walking, and keeping the gentle pace of the group with limited opportunities to sit.
Adults Exclusive Cave Walk
$29.95
Offered on Select Days
Express walk through the cave to the waterfall for guests age 15 and older
Participants should be comfortable walking, standing, and keeping pace with the group for up to 90 minutes.
Geology Tour
$40.95
Offered on Select Days
Immersive specialty tour with early-access
Appropriate for guests age 5 and older
Participants should be comfortable walking, standing, and keeping pace with the group for up to 120 minutes.
Annual Pass
Adult - $54.95
Child - $34.95 (Ages 4-12)
How Long Should You Plan to Spend?
The standard Cave Walk lasts approximately 90 minutes but definitely allow additional time for the tower, overlooks, photos, and food or shopping. Ruby Falls estimates that many visitors spend around 2–3 hours at the attraction.
What to Wear
You'll be doing a fair amount of walking on uneven surfaces so be sure to wear comfortable walking shoes with good grip.
Since the cave stays around 60°F, you'll want a light layer to keep you warm
Clothing suitable for walking and occasional steps.
Accessibility and Things to Know Before You Go
The cave is not wheelchair- or stroller-accessible due to its natural formations, narrow passages, and steps.
Standard cave tours require walking, standing, and keeping pace with the group.
There are low ceilings, darkness, changing lights, music, and crowded or enclosed areas.
A Low Sensory Cave Walk is available by request with advance notice.
Photography is allowed, but stopping opportunities on the standard Cave Walk are limited.
Where to Stay
There are plenty of options for where to stay in Chattanooga no matter what price range you're looking for. While I didn't have the chance to stay there, here are a few spots that I think are worth checking out.
Cave Walk to Waterfall Tour Experience
After debating which tour to take, I opted for the traditional Cave Walk to Waterfall tour. Partially because that was the only one that was available when I wanted to go and partially because I want to experience the traditional tour.
I didn't know what to expect from the cave aside from the waterfall but, wow, this cave truly amazed me! I arrived early for my tour time which allowed me to explore the grounds a bit and go up the to top of the Castle Tower. This is included in your ticket and I highly recommend going! The views out over Chattanooga are spectacular!
When it was time for the tour, the guides checked us in are off we went. First you take the elevator deep underground. Since it is fairly small, the guide would take us down in small groups. Then after a brief introduction to the cave and safety briefing, we were off. The walk through the cave was one of the most interesting I've ever done. It was interesting one because of all the truly amazing formations and two because it was the only cave tour I've done where out and back traffic took the same route so we were constantly have to pass other groups in narrow spaces.
When we reach the falls cave, the guide informed us that the lights were on a timer but not to worry, there would be plenty of time for the group to get pictures. She then hit the lights which started a light show for the falls. The reveal of the falls was very dramtic and I heard so many gasps and wows froms the group. It really was a spectacle to see. I've never seen anything like it before. And the guide was right. I took pictures, admired the falls, wandered around, and still had time to go back for more pictures.
Final Thoughts
I've toured a lot of caves over the years and I honestly expected this to be a sub-par tour aside from the waterfall. Boy was I wrong! The cave itself was filled with so many amazing formations that by the time I made it to the waterfall, I was already in awe. The waterfall just became the icing on the cake at that point, rather than the only attraction. I highly recommend this tour to everyone whether your cave enthusiast for not. This is the perfect additional to any Chattanooga vacation.
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