Last Updated: August 3, 2026
Kentucky gave us two stops that have almost nothing in common except that both are underrated. Cumberland Falls throws a moonbow — a lunar rainbow — on clear nights around the full moon, and it is one of only two places on earth where that happens on a predictable schedule. Mammoth Cave is the longest cave system in the world by a very wide margin, and it is still getting longer every year as surveyors push further into it. Between the two of them we found the original Kentucky Fried Chicken and a Stonehenge in somebody’s front yard. From Pigeon Forge it was a straightforward run north.
Cumberland Falls
Cumberland Falls is the second largest waterfall east of the Rocky Mountains, and by volume of water it is the largest in the eastern United States south of Niagara. It measures 68 feet high by 125 feet wide. People here call it the Niagara of the South, and on a full river that is not the overstatement it sounds like.
It’s spring and we had recent rains, so the river was full and stunning to see. Flow here swings enormously — the gauge record runs from around 1,300 cubic feet per second in a dry year to over 5,000 in a wet one — and the difference between a good day and a disappointing one at this waterfall is entirely down to what fell upstream the week before.
The Moonbow
This is what Cumberland Falls is famous for and the reason to plan a trip around a calendar rather than a weekend. A moonbow is exactly what it sounds like: a rainbow made by moonlight instead of sunlight, refracting through the mist thrown up by the falls. Because moonlight is so much fainter, the human eye registers it as a pale silver-white arc rather than a band of colour — though a long camera exposure will pull the colours out of it.
Moonbows have been recorded at Yosemite Falls, in Costa Rican cloud forest, and elsewhere, but they need a very particular combination — a bright moon low in the sky, clear air, real darkness, and a permanent curtain of mist. Only two places on earth deliver all four often enough to put on a schedule: Victoria Falls in Africa, and here. Cumberland Falls is the only place in the Western Hemisphere where the moonbow appears with regularity.
It runs for roughly two nights either side of the full moon, best after full dark, and it needs a clear sky and decent flow. The state park publishes a moonbow calendar for the year. There is no moonbow in any of our photographs — plan better than we did.
There is a good reason this waterfall still exists. In the 1920s a power company held rights to dam the Cumberland just above the falls, which would have drowned them. A campaign to stop it ran for years and eventually reached T. Coleman du Pont, a Kentucky-born member of the Delaware chemical family, who offered to buy the falls and hand them to the state. He died before the deal closed. His widow completed it, purchasing the falls and 593 acres for $400,000 in March 1930, and Cumberland Falls was dedicated as a state park on August 21, 1931. The Civilian Conservation Corps built much of what you walk on today, including the lodge that still carries the du Pont name.
The lichen on the rock in the first frame is doing something quietly remarkable, incidentally. Lichen is not one organism but two living as one — a fungus providing the structure and a photosynthetic partner, an alga or a cyanobacterium, providing the food. It is the first thing to colonise bare rock and it slowly breaks that rock down into the beginnings of soil.
The adjacent Cumberland Falls State Resort Park has a lodge and a restaurant, but unfortunately it wasn’t open for the season yet. It would have been nice to enjoy a dinner there.
We stayed at Laurel Lake Camping Resort outside Corbin. They had full service. There was hardly anyone there and the property was large and quiet. The area was very isolated, so there was very little to do other than visit the waterfalls — which suited us. Laurel River Lake next door is an Army Corps of Engineers reservoir on the Laurel River, and the reason this pocket of Kentucky is so empty is that most of the land around it is Daniel Boone National Forest.
Kentucky Fried Chicken: The Original
Harland Sanders started what became Kentucky Fried Chicken here in Corbin, and the vintage gas pumps out front are not decoration. He arrived in 1930 and took over a service station on US 25, and because there was nowhere for travellers to eat he began feeding them at his own dining table in the back — six seats. The food outgrew the filling station. He built a proper 142-seat café in 1937; it burned down two years later; he rebuilt it with a motel attached and reopened on July 4, 1940. There was a model motel room built into the restaurant so that diners could see what they would be sleeping in.
The seasoning and the pressure-frying method that made the name were both worked out in that kitchen through the 1940s. What killed the business was a road. US 25 was rerouted, then Interstate 75 went through and took the traffic with it. Sanders sold up in 1956, at 65, and went out on the road selling franchises. He is the rare case where the second act is the famous one.
The original location is still a working KFC and also a museum. It was closed for renovations when we visited, which was a bummer — it has since reopened, and you can walk through his office and the original kitchen. We were able to order takeout: an eight-piece chicken tenders with mashed potatoes and gravy, mac and cheese and biscuits. It was absolutely delicious.
Mammoth Cave National Park
Mammoth Cave National Park holds the longest cave system in the world, and more of it is mapped every year. The surveyed total now stands at more than 426 miles of passage — close to twice the length of the second longest, Sac Actun in Mexico, which is largely underwater. It became a national park in 1941, a UNESCO World Heritage Site in 1981 and an International Biosphere Reserve in 1990.
The number keeps moving for a reason. Until 1972, Mammoth Cave and the neighbouring Flint Ridge system were thought to be separate caves, and Flint Ridge held the world record at 86.5 miles. On September 9 that year, six explorers following a passage they named Hanson’s Lost River came up out of the water into a place they recognised — and the two caves became one. Everything since has been survey teams from the Cave Research Foundation adding a mile here and a mile there, weekend after weekend, for seventy years.
We were previously here in March 2020, at the beginning of the COVID pandemic, but our cave tour was cancelled. Two years later COVID was still with us, but at least we got underground. We took the Domes and Dripstones tour, which drops you into the cave through a shaft, runs you down about 280 stairs into a series of vertical domes and pits, and finishes in the Frozen Niagara section where all the formations are.
Why Mammoth Cave Has So Few Formations
The caves were first reported by settlers in the late 1700s. The geology is thick limestone with a sandstone cap, and that cap is the whole story — including the answer to the thing most visitors notice first.
Mammoth Cave sits in three stacked layers of limestone — the St. Louis, the Ste. Genevieve and the Girkin — laid down in a shallow tropical sea more than 300 million years ago. Slightly acidic groundwater dissolved the limestone along joints and bedding planes, and as the Green River cut its valley deeper it drew the water table down with it. Each time the river dropped, the passages it had been draining were abandoned and a new level started forming below. That is why the cave is a stack of dry corridors over an active river.
Sitting on top of all of it is the Big Clifty Sandstone — a hard, largely impermeable caprock. Rain cannot percolate straight down through it. And a stalactite is nothing more than a drip of mineral-laden water arriving at a ceiling and leaving behind what it was carrying, so where no water arrives, nothing grows. That is why so much of Mammoth Cave is huge, dry and bare, and why it looks so different from Carlsbad Caverns. Where the caprock has been breached — a valley cut through it, a sinkhole — water gets in and the cave suddenly decorates itself. Frozen Niagara is exactly such a spot, which is why every formation photograph on this page comes from the same end of the tour.
Even though Mammoth Cave does have formations — stalactites, stalagmites, columns, draperies and bacon — they are not as prevalent as in caves like Carlsbad Caverns. “Bacon” is the real term, by the way, and once you have seen a backlit sheet of it you never forget why: a drapery thin enough to glow, with rust-coloured bands running through it where iron-rich water came through in pulses.
And this is a cave cricket — Hadenoecus subterraneus, the animal the whole underground food web is built on. A cave with no light has no plants, so nothing down there can make its own food; every calorie has to be carried in from outside. Cave crickets do the carrying. They roost near the entrances by day, leave at night to forage in the forest, and come back in, and what they bring back — droppings, eggs, and eventually their own bodies — feeds everything else. Blind cave beetles hunt their eggs. Take the crickets out and the ecosystem collapses. Around 130 species have been recorded in this cave system, and several of them, including the endangered Kentucky cave shrimp and two species of eyeless cavefish, exist nowhere else.
Stephen Bishop, Who Mapped It
Almost everything known about this cave in the nineteenth century was found by an enslaved man. Stephen Bishop was brought here in 1838 at seventeen, owned by the lawyer who had just bought the cave, and put to work as a guide. In his first year he did the thing nobody had managed: he laid a ladder across the Bottomless Pit and crawled over it, opening up miles of passage on the far side that no one had reached. He went on to name River Styx, Lake Lethe and the Great Relief Hall, and he found the eyeless fish.
In 1842 he was taken up to his owner’s plantation and asked to produce a map. He drew the entire cave from memory over about two weeks. Published in 1844, it was the standard map for more than forty years — and it showed a passage connection that was not proven until 1972. He taught himself to read partly off the smoke-written signatures visitors left on the cave walls. Visitors described him as the most interesting thing in the cave. He was freed in 1856 and died the following year, at about 37, and is buried in the Old Guides’ Cemetery on the hill above the entrance under a headstone that gets his death date wrong.
Saltpetre, a Tuberculosis Ward, and the Cave Wars
Before it was a tourist attraction it was a factory. During the War of 1812 the British blockade cut off imported gunpowder, and the nitrate-rich sediment on the floor of Mammoth Cave became strategically important. Enslaved workers dug the dirt, leached it in great wooden vats to extract calcium nitrate, and piped the liquor out through hollowed logs. Some of the vats and the log pipeline are still in place. Those same workers cut the first trails, laying flat stones so ox carts could get through.
Then, in 1842, Dr. John Croghan — who owned the cave, and had tuberculosis — decided the cave’s constant temperature and clean air would cure consumption. He had stone cottages built underground and moved sixteen patients in. They improved briefly and then got much worse: the damp air and the soot from lard-oil lamps were about the worst possible environment for a damaged lung. Five died. The experiment was abandoned within five months. Two of the stone huts are still standing in the passage, and Croghan himself died of tuberculosis a few years later.
The last chapter before the park is the strangest. By the 1920s more than twenty rival show caves were operating in this one corner of Kentucky, in an era known locally as the Kentucky Cave Wars — lawsuits, sabotage, and men called “cave cappers” stationed along the roads to flag down motorists and steer them to the wrong cave. In 1925 a cave explorer named Floyd Collins got pinned by a rock in a crawlway at Sand Cave. The rescue attempt ran for eighteen days and became one of the biggest news stories of the decade, with reporters and crowds camped on the hillside. He died down there. The publicity, more than anything else, made a national park inevitable. Congress authorised it in 1926 and it was established in 1941 — and, exactly as in the Smokies, the land had to be bought. Some was purchased with donated money and some taken by eminent domain, and families lost farms, churches and cemeteries in the process.
There is a subterranean waterway down there too. Boat trips on Echo River were one of the great Mammoth Cave experiences for over a century, until they were discontinued in the early 1990s.
Kentucky Stonehenge, Munfordville
Kentucky Stonehenge is in Munfordville, about twenty minutes north of Cave City, and it is part of someone’s yard. It was built by a local man named Chester Fryer, who spent years hauling stone off more than a thousand acres of Hatcher Valley and arranging it on his own property — the henge is only one section, alongside rock gardens and a Garden of Gethsemane. It doesn’t appear to be an accurate representation of Stonehenge in England, but it was still pretty impressive. The public can visit during daylight hours, free, with a voluntary donation. Look, don’t climb.
Singing Hills RV Park, Cave City
We’ve stayed here before. They have full hookups and WiFi good enough to stream.
Singing Hills is just outside Mammoth Cave National Park. Daffodils were blooming. We enjoyed a couple of beautiful sunsets. Worth knowing, given where we had just been: daffodils are not native anywhere in North America, so a clump of them in this landscape usually marks a spot where somebody’s front door used to be — the same story we found written across the Smokies the week before, and the same story the families bought out of Mammoth Cave in the 1930s could tell.
We spotted a four leaf clover on St. Patrick’s Day. Pretty special — and rarer than the folklore suggests is generous. The fourth leaflet comes from a recessive genetic trait switched on by growing conditions, and the usual estimate is about one stem in five thousand. Finding one in a patch of grass on that particular day felt like the universe showing off.
Visitor Information
Mammoth Cave National Park. Entrance fee: none. Cave tours: ticketed and the only way to go underground — the Domes and Dripstones tour runs about $30 adult, $25 youth 6–12, $8 for ages 3–5, with the full range of tours from around $12 to $79. Book ahead at Recreation.gov or 877-444-6777; summer and holiday tours sell out. Camping: Mammoth Cave Campground around $25 a night, Houchin Ferry $20, Maple Springs group sites with hookups $50; backcountry permit $10. Interagency Senior and Access pass holders get 50% off tours and camping. Biosecurity: because of white-nose syndrome in the bats, you will be asked whether you have been in another cave and will walk over a decontamination mat on the way out. Don’t wear boots or clothing you have worn in another cave.
Cumberland Falls State Resort Park. 7351 Highway 90, Corbin, KY. Admission: free. Open: daily, with the overlooks lit at night during moonbow viewing. Moonbow: roughly two nights either side of the full moon, after full dark, clear skies required; the park publishes a calendar for the year on the Kentucky State Parks site. Bring a tripod. On site: DuPont Lodge and the Riverview restaurant, cabins, campground, hiking, and rafting outfitters on the Cumberland below the falls. Check seasonal opening dates — the lodge restaurant was not yet open when we came through.
Harland Sanders Café and Museum. 688 US Highway 25W, Corbin, KY. A working KFC with the original 1940 café preserved alongside it — Sanders’ office, the original kitchen, the model motel room and a good deal of memorabilia. Free to walk through. It was shut for renovation during our visit and has since reopened.
Kentucky Stonehenge. Lynn Avenue, Munfordville, about twenty minutes from Cave City. Private property, open dawn to dusk, free, donations welcome. Please don’t climb on the stones.
Laurel Lake Camping Resort. Corbin, KY — still operating. Full hookups, large sites, quiet, about twenty minutes from Cumberland Falls.
Singing Hills RV Park & Campground. 4110 Mammoth Cave Road, Cave City, KY — still operating. Full hookups, usable WiFi, a few minutes from the park entrance road.
Tips
Plan Cumberland Falls around the moon, not the weekend. Check the park’s moonbow calendar first and build the trip around it. Two nights either side of full, clear sky, decent flow. It is the single thing that makes this waterfall different from every other waterfall in the country.
Reserve your cave tour before you reserve your campsite. Tours are the only way into Mammoth Cave and they sell out well ahead in season. Pick the tour first and build the days around it.
Know what you are buying with each tour. Domes and Dripstones is the one with the formations, and it has around 280 stairs. The Historic tour is big passage, saltpetre works and the TB huts, and more history. Frozen Niagara is short and mostly formations. If you only do one and you want the pretty pictures, take the one that ends at Frozen Niagara.
The cave is 54°F all year. That is a shock in July and a relief in January. Take a layer whatever the surface is doing, and wear shoes with grip — the passages are damp and the stairs are steel.
Photography underground: no tripods on the tours and no flash in most places. Push the ISO, brace against a railing, and accept some grain. The lighting is fixed and reasonably good in the Frozen Niagara section.
Go after rain for the falls, and after dry weather for everything else. Cumberland Falls at low water is a fraction of itself. We had recent rain and it made the visit.
Frequently Asked Questions
What is a moonbow, and when can you see it at Cumberland Falls?
A moonbow is a rainbow formed by moonlight refracting through mist rather than by sunlight. Because moonlight is faint, the eye usually sees a silvery-white arc; a long camera exposure reveals the colour. At Cumberland Falls it appears for roughly two nights either side of the full moon, after dark, on clear nights with good water flow. The state park publishes an annual moonbow calendar.
Where else in the world can you see a moonbow?
Moonbows occur occasionally at Yosemite Falls, in Costa Rican cloud forest and at a handful of other misty places, but only two locations on earth produce them predictably enough to schedule: Victoria Falls in Africa and Cumberland Falls. Cumberland Falls is the only reliable one in the Western Hemisphere.
How long is Mammoth Cave?
More than 426 surveyed miles, and growing. That is close to twice the length of the second-longest known cave, Sac Actun in Mexico. The figure jumped in 1972 when explorers proved that Mammoth Cave and the neighbouring Flint Ridge system were one cave.
Why does Mammoth Cave have so few stalactites and stalagmites?
A hard sandstone caprock, the Big Clifty Sandstone, lies over most of the cave and stops rainwater percolating down into the passages. Formations are built by dripping water, so where no water gets in, nothing grows. Where the caprock has been breached — Frozen Niagara, for example — the cave is heavily decorated.
Is there an entrance fee for Mammoth Cave National Park?
No entrance fee. Cave tours are ticketed separately and are the only way to get underground, ranging from about $12 to $79 depending on the tour. Reserve in advance.
Who was Stephen Bishop?
An enslaved guide brought to Mammoth Cave in 1838 at seventeen, who explored and named much of the cave, crossed the Bottomless Pit to open miles of new passage, discovered its eyeless fish, and in 1842 drew a map of the whole system from memory that stayed authoritative for over forty years. He is buried in the Old Guides’ Cemetery above the entrance.
Can you visit the original KFC in Corbin?
Yes. The Harland Sanders Café and Museum on US 25W is a working KFC built around the preserved 1940 café, with Sanders’ office, the original kitchen and the model motel room. It is free to look around, and it reopened after the renovation that had it closed when we came through.
Next stop: Land Between the Lakes NRA, Kentucky.
