| 1 | Gua Wang, Malaysia |
Gua Wang is located on the southern border of Thailand, opposite Peninsular Malaysia. Located in the forested Perlis National Park, the cave is under mankind’s control as much as a cave can be, with detailed wooden signs at the entrance and a metal walkway throughout.
Visitors are handed helmets with torches, and given a choice of two caves: the easier passage 1, or the tighter, more physically taxing passage 2. The gimmick is being able to enter a passage in Malaysia and emerge from the other side in Thailand, if you can suppress your claustrophobic panic instincts for long enough.
Gua Wang cave is ecologically rich, littered with insects, stalactites, and of course, shed reptile skins. The first snake here is Ridley’s cave racer, which is probably the most cave-adapted snake in the world. This is a subspecies of the non-venomous beauty ratsnake, which is ghostly white, has a red tongue, and has adapted to feeding on bats.
The second native species is much rarer, and was discovered only in 2014. It’s called the Gua Wang Burma wolf snake, or Lycodon cavernicolus, and is known solely from this cave.
The first two individuals were discovered 200 metres deep within the cave, in total darkness, and 2-3 metres high on the wall. The maximum length discovered was 50.8cm, and the species proved to be genetically distinct from the Butler’s wolf snake living nearby.
Most wolf snakes have black and white bands, but the Gua Wang Burma species is much plainer. No fresh locations have been discovered for this species since 2014 – Gua Wang Burma cave remains their sole confirmed habitat.
| 2 | Kantemó Bat Cave |
The Kantemó Bat Cave is found on Mexico’s Yucatan peninsula, near a tiny Mayan settlement with just one church. For decades, the local Mayans refused to enter this cave, believing it to be haunted by evil spirits. In October 2003, Bayona Miramontes had different ideas, and he decided to explore the cave for the first time, with three friends. What he found was an ecological haven: 7 species of bats, and a vast amount of yellow-red ratsnakes.
The spot is now known as “hanging snake cave” and has a 65 foot wide entrance. The snakes and bats have an intricate relationship. By night, the bats fly out in their thousands to feed in Lake Chichancanab two miles away. The snakes then position themselves, hanging silently from the dark entrance.
As the bats return, the slightest brushing triggers the snakes’ hunting instincts, causing them to grab the bats with their mouths and devour. The thousands of snakes live in crevices high in the cave’s walls and ceiling. Sometimes, the snakes will break the wings of larger bats, and drag them deep into these dark crevices.
This cave also contains the blind brotula, a blind transparent eel, and originally contained ancient Mayan pots. The Kantemó Bat Cave is now home to ever-increasing tourists, but the snakes continue their hunting unabated.
| 3 | Well of hell, Yemen |
The Well of Hell is one of Yemen’s most amazing natural landmarks. It’s a 150 metre wide pit just over the border from Oman, an unexplained natural black hole in the centre of a bone dry desert.
Local superstition about this pit is endless; they believe it to be a portal to hell, a prison for genies, or a supervolcano capable of destroying the Earth. An unexplained foul smell emanates from the pit, which some theorise to be the souls of the damned. Some say that the sinkhole can suck people in if they stray too close.
In 2021, Mohammed Al-Kindi and 7 colleagues rappelled down the pit, in order to discover the truth once and for all. Their previous record was 50-60 metres down, but this time, they descended to the very bottom, safety be damned.
Al-Kindi and his team didn’t find genies or cursed spirits. Instead, the well was a total snake pit. There were slithery serpents all over the floor, along with dead birds, stunning green pearl formations, and lots of stalagmites.
Fortunately, the research team managed to escape with their lives: “There were snakes, but they won’t bother you unless you bother them” said Al-Kindi. Another amazing feature was secret waterfalls, which started from 65 metres deep in the cave and plunged to the bottom, invisible to those above. According to Al-Kindi, the cave smelled fine from within.
| 4 | Snake Palace (Istana Ular) |
An Indonesian chamber of nightmares, which might be the single worst place on Earth. Istana Ular is located on East Nusa Tengarra, one of the more easterly Indonesian islands. It’s a long, straight, semi-flooded tunnel which stretches for hundreds of metres into a limestone hillside by a river.
Istana Ular is believed to be an ancient lava tube, forged by violent magma expulsions long ago. The cave is home to a colony of reticulated pythons, the longest snake species on Earth. Locals refuse to go anywhere near this cave, believing that the pythons flock out en masse in the rainy season and snatch their cats and dogs.
The entrance is black and unforgiving, and when you enter, the horror somehow outstrips its reputation. Reptile expert Brady Barr entered this volcanic tube in 2007 with his compatriots. The chamber was stifling, and the oxygen severely reduced. The entire tunnel was full of waist high bat slurry, forcing them to wade through the shallower right side of the tunnel. There were maggots, roaches, spiders, lizards, and thousands of squeaking bats themselves.
Worse was that the cave was home to several 3 metre long reticulated pythons. Barr attempted to grab the tail of one as it slid through a crack in the wall. This was a mistake, as the furious python instantly swivelled 180 degrees and began coiling around Barr.
He later said that the python’s power was astonishing, and in the melee, he felt the snake’s fangs sink into his left thigh. He let out an ear-piercing scream, and in the stifling heat of the slurry-filled cave, it was all he could manage to not faint. The python continued biting, and tore downwards through his flesh.
Eventually, Barr and friends fled the cave, and reached a Singapore hospital, which wisely recommended not fully sewing the wound closed, in order to prevent infections from the vile snake chamber from being locked in.
The whole python bite incident was captured on film. Watch it, if you must.
| 5 | Brandon Hill Cave, Honduras |
A famous bat cave found on the Honduran island of Utila. According to legend, Caribbean pirates stashed their treasure here in the 16th and 17th centuries, including legendary Welsh pirate Henry Morgan. Locals believe that gold coins and riches are still hidden somewhere within the cavern, and are determined to find them.
Brandon Hill Cave is surrounded by forest, and is a cavernous limestone cave with 8 main chambers. It stretches 80 metres deep into the hillside, but could be even longer, as that only covers the areas passable by humans. Brandon Hill Cave is home to 6000 bats of 4 different species, including Merriam’s long-tongued bat and Tome’s sword-nosed bat.
The snake here is the yellow-red ratsnake (Pseudelaphe flavirufa), the same species which dominates Mexico’s hanging snake cave. This large serpent has a strong tail which can bind to the cave’s roof and dangle down like a vine made from stone. In Brandon Hill Cave, they have a strong taste for one particular bat: the Mexican greater funnel-eared bat (Natalus mexicanus).
Yellow-red ratsnakes have been found 40 metres deep in Brandon Hill Cave before. 5 have been seen hunting bats at once; these snakes had congregated in a particularly narrow part of the chamber, forcing the bats to funnel towards them.
| 6 | Langun-Gobingob Cave |
Langun-Gobingob is the one of the longest caves in the Philippines, with 12 large chambers and 7 kilometres of passages. This is a dark cavern of spikes and pillars, plus endless roosts of bats, and a strange organic smell which tells you instantly that this is a living ecosystem. There’s rock formations galore, including a flowstone the size of a small skyscraper, made up of sparkling calcite crystals.
One of the chambers in Langun-Gobingob is as large as football pitch, before switching to tight, claustrophobic crawlspaces in mere seconds. All visitors must be equipped with a helmet-mounted headlamp, and what’s more, they’re not alone: snakes are watching from every corner.
The common species in Langun-Gobingob is the Müller’s rat snake (Stegonotus muelleri). This snake is 1 metre long, black-yellow in colour, and thankfully non-venomous. According to reports, visitors to Langun-Gobingob have been forced to drag snakes out of tight crawlspaces, or even wait for an hour for them to slither away of their own accord.
Visitors to this cave are forced to sleep in tents with the knowledge that the ratsnakes could slither right past them. The lower Langun caverns even have an area called the Snake Room where the species congregates. This is accessible by a 3 metre rappel downwards, with little light to guide you. Fortunately, Müller’s ratsnake is a non-aggressive species, with no ill will towards humanity.
| 7 | Cueva Castillo, Ecuador |
This Ecuadorian cave shot to global headlines in 2016, when the rainbow boa (Epicrates cenchria) was observed hunting a vampire bat for the first time.
The common vampire bat relies solely on blood, not of humans sleeping in their beds, but of birds. Rather than dangling from stalactites, the rainbow boa was filmed plucking a vampire bat from the air from a ground position. It applied its coils, and the bat ceased to struggle within 2 minutes, yet the cautious boa clung on for another 7 minutes. It then swallowed the bat, which took 4 minutes and 50 seconds.
Castillo Cave is located near the Ecuadorian city of Tena. The cave isn’t remote, as one of its entrances lies just 60 metres from the road. However, dense jungle lies between, which hides the entrance from view.
There are three entrances in total: a northern, western, and eastern entrance. This is a tight cave, as the highest chambers only reach 3 metres tall, which are where the bats tend to congregate. So far, this snake cave measures 450 metres deep, and that’s only the sections which have been mapped out.
| 8 | Persistence Cave |
Persistence Cave lies in South Dakota, with a tiny, pitch black entrance. The narrow caverns are filled with animal bones dating back 42,000 years, including pikas, frogs, black bears and bison. It’s a treasure trove for archaeologists, but there’s one small problem – this cave is a prime den for prairie rattlesnakes.
Persistence Cave was first discovered in 2004, when Marc Ohms saw a small alcove at the end of a ridge. He shifted a few boulders to reveal the entrance, and was instantly greeted by poison ivy and hissing rattlesnakes. He left the cave alone, assuming that it was a mere snake den, but the hole turned out to be a fully fledged cave, 40 miles long if air pressure movements were to be believed.
The pull of history lured Ohms back in, snakes be damned. Soon after, excavations began which are still continuing to this day, despite the constant venomous threat. In 2016, Marc Ohms was 50 feet deep in the cave, when he turned around and came face to face with a rattler 2 feet away, within easy striking distance.
“We have to double check to make sure the rattlesnakes are not in our face, literally,” said Dr Jim Mead, lead researcher. The rewards are irresistible though – researchers regularly drag out bags containing hundreds of ancient bones.
| 9 | Cueva de los Culebrones, Puerto Rico |
In English, this name translates to “cave of the boas”, so don’t say they didn’t warn you. The Cueva de los Culebrones lies inside the protected Mata de Plátano reserve of Puerto Rico, a moist forest region of karst limestone, with an abundance of barely explored caves. Rather than a cold, dripping cavern, this is a hot cave, with a 5 metre wide, 3 metre high entrance.
The main passage is 182 metres deep, with 3 separate chambers. As for the snakes, the species here is the Puerto Rican boa, one of the most cave-loving species in the world. The boas in Cueva de los Culebrones can hang out anywhere from inside the cave, to the dark entrance, to the tall trees beyond the entrance.
Scientists examined Cueva de los Culebrones specifically in a study from 1994-96. Puerto Rican boas have strongly prehensile tails, which they used to dangle from the cave’s limestone entrance. They lowered 75% or more of their bodies down, and when gigantic bat flocks flew past, they swung upwards to grab them, with their tails still gripping firmly. If successful, the boas instantly wrapped around two full body coils, with the boa’s head submerged inside the coil.
The top boa at Cueva de los Culebrones managed to eat 4 bats in a single night. With over 300,000 bats estimated to inhabit the hot, humid cavern, this makes for a virtual buffet, and a huge amount of boas congregating at once, like the snake equivalent of grizzly bears eating salmon by an Alaskan river.
The bats in this cave are divided into 5 or 6 species – the largest is the Antillean fruit-eating bat, but the boas’ favourite in the study was the buffy flower bat.
| 10 | Racer cave, Gunung Mulu |
Gunung Mulu is a jungled national park in the Malaysian section of Borneo. It’s full of treacherous caves, including “advanced” level one caves like Clearwater Connection and Sarawak Chamber, yet the most snake-infested is only rated as intermediate. It’s called “racer cave”, and once again, the signature species is the non-venomous beauty ratsnake (Elaphe taeniura).
The snake trouble starts on the trek in, where you’re stepping over pitvipers and dodging vine snakes pouncing from trees. Then you reach the cave itself. Rather than a nightmarish Halloween attraction with boas swinging from the entrance, this is a darker, quieter cave. It’s filled with stalagmites, plus the eroded bases of dead stalagmites, and ten minutes in, the snakes start to appear. They appear in alcoves in the walls, between rocks in the corner, or even on the ceiling, where they poke their heads out of small holes curiously.
The beauty ratsnake has immense climbing skills, and can reach almost anywhere. As you crawl deeper into the cave, you’d be very unlucky to miss the pale, glowing snakes on all sides.
Racer cave is filled with tight crawlways, and is pitch black, illuminated solely by the headlights of (possibly terrified) visitors. Beauty ratsnakes are harmless, but whether the tour guides tell people that remains to be seen.