Buzz
Caves aren't just havens for bats and ancient skeletons anymore. While many caves boast breathtaking natural beauty and fascinating histories, some even shelter unexpected and cool finds.
10. Underground Mountain Biking
Located in Louisville, Kentucky, the Mega Cavern Bike Park features the world’s first underground mountain biking course, as well as the largest indoor bike park ever built. This park offers trails and challenges suitable for riders of all skill levels, including expert cyclists who can tackle advanced trails with 30-meter-high (90 ft) ceilings. Co-owner Jim Lowry explains, "Imagine riding or skiing down a mountain. You don’t just zoom straight down—you go back and forth, through bumps and smooth patches. At some points, you’re speeding, at others, you slow down."
Mega Cavern Bike Park, designed by bike park creator Joe Prisel, known for his work with the ESPN X Games, is built in a modular layout. This allows the park's trails to be updated regularly, introducing new challenges for bikers. With a constant underground temperature of 16 degrees Celsius (60 °F), bikers can ride comfortably without worrying about dangerous outdoor weather. There will also be a riding school on-site.
The 92-acre cavern also features a business park and exciting attractions like Lights Under Louisville, a stunning drive-through display showcasing over two million Christmas lights. The cavern extends beneath the Louisville Zoo and various commercial buildings, but the diverse textures of the high limestone walls and dirt create an outdoor-like atmosphere, making you feel as though you're above ground instead of deep underground.
With solid limestone overhead, the cavern was deemed secure enough to serve as a fallout shelter for up to 50,000 people during the Cuban Missile Crisis. Originally dug out in the 1930s, this man-made cavern, the largest in Kentucky, was used as a limestone quarry for over 40 years. After changing ownership in 1989, it eventually became home to a recycling center and over 11 acres of office buildings, evolving into a massive complex almost entirely hidden within towering limestone cliffs.
9. An Underground Nightclub
Part of Hotel Las Cuevas in Trinidad, Cuba, Disco Ayala offers a unique rave experience within a cave. Featuring three bars and five dance floors, the club blasts a mix of disco and salsa music from a DJ booth, with colorful lights illuminating the stalactites on the walls. Although some of the heat from the intense disco atmosphere escapes through a large opening in the ceiling, this gap primarily prevents the sound waves from causing a cave-in. The club can accommodate up to 5,000 people and features live performances, including acrobatics, glass-eating, fire-walking, and snake shows.
A popular legend suggests that the cave once served as the hideout of infamous Cuban serial killer Carlos “Coco” Ayala, who kidnapped and murdered children there. Cuban mothers still warn their misbehaving children, "Be good or Carlos Ayala will come for you!" The story goes that Ayala fled during the 19th-century Cuban War of Independence and hid in the cave for protection. An old resident of Trinidad recalled, as quoted by Cuban newspaper Escambray, “I always heard that this man [abducted] children, leading them to a cave to rape and kill them as part of a ritual to the saints.” His reign of terror ended when locals captured and beheaded him. While the full truth of the legend is uncertain, historical evidence supports the claim that Ayala did kill multiple people in the cave during the late 1800s.
Interestingly, the owners of the nightclub chose to retain the Ayala name. However, the disco was built purely for entertainment purposes, with no intention of honoring the dark legacy of a murderer.
8. An Underground Church
The Spassky Cave Church, located in the Russian village of Kostomarovo in the Voronezh region, remains a mystery in terms of its exact origin. It's the larger of two churches within the ancient cave monastery known as the Svyato–Spassky Convent. Carved into a chalky cliff, the church can hold up to 2,000 people. It even houses a 'Cave of Repentance,' where sinners can make confessions. Surrounding the church are areas named after biblical locations, including a Calvary, Gethsemane Garden, a hill of Golgotha, and Mount Tabor.
Before Christianity became widespread in Russia, monks sought refuge in ascetic cave cells throughout the region to escape religious persecution. These cells existed until the first monastery was built in the 12th century. One of the monastery’s key purposes was to protect its parishioners from enemy attacks, even during prolonged sieges. Monks and hermits lived in small, isolated cells carved into the walls of the shrine, with little contact with the outside world, save for a small window chiseled into the rock.
When the communists came to power, the monks were executed, and the Svyato-Spassky Convent was closed, as were many other religious sites across the country. However, during World War II (known as the “Great Patriotic War” in the Soviet Union), the caves once again became a sanctuary, this time providing refuge for Soviet soldiers fighting the Nazis. Though the churches reopened in 1943, Nikita Khrushchev later ordered their closure in the early 1960s. The caves were flooded, and the exteriors of the buildings were burned.
Following the fall of communism in 1993, the church, convent, and caves were reconstructed. Even today, some Russians make an annual pilgrimage to the church.
7. A Completely Unique Ecosystem
The Er Wang Dong cave in Chongqing province, China, is so vast and isolated that it harbors a distinct ecosystem, complete with its own weather system. Scientists weren’t able to explore its depths until 2012, mainly because of the specialized equipment required to descend more than 250 meters (820 ft) through a narrow opening at the cave’s top. Once inside, the explorers discovered additional openings to the outside along the cave’s floor. However, what truly amazed the scientists was not the almost 13-acre size of the cave, but the clouds that blocked their view of the ceiling in an area known as Cloud Ladder Hall.
Clouds can enter, but they’re unable to escape. While the cave had been mined for nitrate near its entrances, the interior chambers were filled with lush vegetation, including trees. However, there’s also danger in the form of rushing rivers that could sweep you away over one of the cave's interior waterfalls, leading to a potentially deadly fall.
Explorer Robbie Shone points out that we still know very little about the secrets of the world’s caves. “More people have visited the Moon than have explored some of these caves,” he remarks. “Every time we venture into these caves and bring back photographs or video, it’s all new material we’ve never encountered before.”
6. The Return of Modern Cavemen and Cavewomen
Over 30 million people in China still reside in caves, with an entire community in Shaanxi province. The loess plateau’s porous soil allows for easy excavation of cave homes, known as yaodong, from the mountainside. These simple, one-room dwellings often use rice paper or quilts as makeshift doors. For those who can afford it, additional rooms, electricity, running water, and even a yard are available. These caves help conserve energy and offer more land for farming.
Some caves are highly sought after for purchase or rent, but surprisingly, few people want to leave. Most cave dwellers have spent their entire lives there, and even those who have moved on often dream of returning. “It’s cool in the summer and warm in the winter,” says Ren Shouhua, in his forties. “It’s quiet and safe. When I get old, I’d like to go back to my roots.”
However, living in caves hasn’t always been without risk. On January 23, 1556, the Shaanxi magnitude 8 earthquake struck, becoming the deadliest earthquake ever recorded. It claimed 830,000 lives, many of whom perished when their yaodong homes collapsed.
Despite this, caves have provided a safe haven for the Chinese during crucial historical moments. Mao Zedong sought refuge in caves in northern Shaanxi province when the Long March ended in the 1930s. American journalist Edgar Snow described a Red Army university built inside bombproof caves. Even Chinese President Xi Jinping spent seven years living in exile in a cave in Shaanxi during the Cultural Revolution.
However, not all modern cave homes are simple or inexpensive. The Cave House in Bisbee, Arizona, was listed for over $1 million in 2012 after one of its owners passed away. It’s even possible to find a cave home for sale on eBay, as Curt Sleeper did in 2003 in Festus, Missouri. He quickly learned that getting bank financing for a cave purchase was challenging. The Sleepers moved in but eventually faced financial hardship and had to put the house up for auction.
5. Medical Treatment Centers
When two middle-aged women from France became convinced that modern electromagnetic radiation was affecting their health, they decided to live in a cave. “I’ve been treated like a crazy woman,” said Bernadette Touloumond, one of the pair. “I’ve lost a lot of friends, and my family finds it hard to understand.” Despite this, people from all over the world visit treatment centers located in caves, hoping to find relief from various health issues. One such center is the Gastein Healing Cave in Austria, which houses the world’s largest pain management facility.
In recent times, salt caves have gained popularity for treating respiratory problems like asthma and skin conditions such as eczema. Some of these caves are natural, while others are man-made, designed with walls and ceilings covered in salt. In some cases, a generator blows salt particles into the air. In these halotherapy chambers, individuals sit back and inhale the salt-infused air. However, doctors warn that for some conditions, like asthma, these treatments may actually worsen symptoms.
A German named Dr. Schutz is credited with originating the idea of a salt 'cure gallery' in Berchtesgaden, Germany, after observing the healing effects of the air surrounding a Polish salt mine during World War II. In Eastern Europe, many people consider salt caves to have therapeutic benefits. However, there is a lack of English-language studies that either confirm or dispute these claims about the health benefits of salt rooms.
4. A Controversial Movie Set
Devetashka Cave, located near the village of Devetaki in Bulgaria, is a vast cavern. In the 1950s, it was repurposed as a military storage facility for oil tanks. The cave also saw human habitation in ancient times, but today, it is home to a protected population of bats, including some endangered species.
In 2011, Devetashka Cave gained notoriety due to a controversy surrounding a film production. The crew of The Expendables 2 (featuring Sylvester Stallone and Bruce Willis) filmed a dramatic sequence in which Stallone crashes a plane into the cave to attack Jean-Claude Van Damme's hideout. Environmentalists raised concerns, claiming the shoot led to a 75% reduction in the bat population. Bulgarian zoologist Nikolay Simov from the Center for Bat Studies and Protection explained, “The shooting harms the bat habitat—with the placement of props, the cutting down of vegetation, as well as disturbance by the presence of large numbers of people and the noise they make.” Simov further stated that the noise caused the bats to prematurely wake from hibernation, damaging their health.
Simov also pointed out that local authorities lacked legal grounds to approve the filming, as regulations restricted the cave to scientific research and tourism only. However, after an investigation, the Bulgarian Ministry of Environment and Waters concluded that most bats were indeed hibernating correctly and that the number of dead bats was not significant enough to warrant alarm.
3. Hidden Treasure
In March 2015, a young member of the Israeli Caving Club uncovered a buried treasure in a cave in northern Israel, though its exact location remains undisclosed. Authorities have opted not to reveal the cave’s whereabouts, fearing that treasure hunters might exploit it for further riches.
While navigating a particularly tight passage with his father and a friend, Hen Zakai noticed something glimmering in the dim light. It turned out to be two silver coins from the era of Alexander the Great, who conquered Israel in the late 4th century BC. Each coin featured an image of Alexander on one side, with Zeus depicted on the reverse. Alongside the coins, Hen also found a pouch containing well-preserved silver jewelry, including earrings, rings, and bracelets.
According to Dr. Eitan Klein of the Antiquities Authority, the valuables may have been concealed by local inhabitants who sought refuge in the cave during a turbulent period following Alexander’s death, when the Wars of the Diadochi erupted among his heirs. The treasure was presumably hidden with the hope that the situation would improve, though it seems the original owner never returned to reclaim it.
Further investigation of the cave uncovered ancient pottery hanging from the stalagmites, some of which had fused with the limestone, rendering it impossible to remove. The artifacts found span from the Hellenistic period, around 2,300 years ago, all the way back to the Chalcolithic period, approximately 6,000 years ago.
2. An Amusement Park
Although not technically a cave, the Wieliczka Salt Mine near Krakow, Poland, no longer functions as a mine either. For over a decade, no salt has been extracted from it. This vast complex stretches for 300 kilometers (186 miles) and reaches nine levels deep, housing chapels and impressive sculptures of historical and religious figures. Dating back to the 13th century, generations of mainly Catholic miners created remarkable underground structures, including a grand cathedral. The mine also features an underground lake and chandeliers crafted from salt. Like other salt caves, Wieliczka has a spa designed to assist individuals with respiratory conditions. In 1978, it was recognized as a UNESCO World Heritage Site.
Adventurous visitors make their way 300 meters (1,000 feet) beneath the surface to enjoy activities like bungee jumping, hot-air balloon rides, and even windsurfing across the salt-filled underground lake (though a large fan is required for the wind). The mine also boasts an underground brass band that plays to entertain guests during their exciting experiences.
1. Astronomical Knowledge & A Fertility Light Show
On the island of Gran Canaria, part of Spain's Canary Islands, a cave has provided evidence of the advanced astronomical understanding possessed by its early inhabitants. This cave, which likely served as a temple, contains markings that align with the equinoxes and solstices, showcasing a sophisticated knowledge of celestial events.
The cave also produces a remarkable fertility light show throughout the year. As archaeologist Julio Cuenca puts it, “It’s like a projector of images from a vanished culture.” The people responsible for this temple were the aboriginal Guanches, who are believed to have arrived in the Canary Islands roughly 3,000 years ago. After Spain’s conquest in the 1400s, their culture gradually vanished.
The cave appears to illuminate ancient fertility myths, displaying images that evolve with the changing seasons. From March to September, sunlight casting onto the cave walls creates phallic symbols over engravings of female pubic areas. As autumn approaches, these images gradually transform into a representation of a pregnant woman, ultimately culminating in the depiction of a seed.
