60 Fun Facts About Caves

Most of the world's caves are formed by the slow dissolving of which rock?

Rainwater charged with carbonic acid eats along cracks and bedding planes; the resulting sinkhole-pocked landscape is called karst.

What is the name for the scientific study of caves?

Recreational exploration is caving, potholing or spelunking; the science's name was coined by Émile Rivière in 1890.

A stalactite hangs from a cave ceiling. What is the matching formation that grows up from the floor called?

An easy memory aid: stalactites hold tight to the ceiling, stalagmites might reach it one day.

Which system in Kentucky has the greatest total length of surveyed passage in the world?

More than 675 kilometres have been mapped, over one and a half times the length of the runner-up, an underwater system in Mexico.

In which country is Sơn Đoòng, the cave with the largest known passage in the world?

A local man found the entrance in 1990 while looking for agarwood, but was put off by the wind and roar of water and did not go back for years.

Bracken Cave near San Antonio, Texas, is the summer home of the largest colony of which animals on Earth?

An estimated 20 million of them roost there from March to October, the largest known concentration of mammals anywhere.

Waitomo Cave in New Zealand is famous for a ceiling lit by thousands of what?

They are the larvae of a fungus gnat found only in New Zealand, dangling sticky silk threads to snare prey drawn to the light.

What are cave visitors told to do to enter the Blue Grotto on the island of Capri?

The entrance is about a metre high at low tide; the Emperor Tiberius used the cave as his private swimming hole.

In 2018, twelve boys and their football coach were trapped for over two weeks in the Tham Luang cave in which country?

Two divers from the UK found the Wild Boars team alive on a ledge two kilometres inside; all thirteen were sedated and dived out between 8 and 10 July.

The Paleolithic paintings of Lascaux, with its Hall of the Bulls, are in which country?

An 18-year-old found the entrance in 1940 when his dog investigated a hole left by an uprooted tree; the original cave has been closed since 1963.

Which site in the Altai Mountains of Siberia gave its name to an extinct human species identified from a finger bone in 2010?

The site also yielded a 50,000-year-old bone needle and a girl whose mother was Neanderthal and father Denisovan.

Fingal's Cave, whose echoes inspired Mendelssohn's Hebrides Overture, is a sea cave on which Scottish island?

It is built of hexagonal basalt columns like the Giant's Causeway; Turner painted it and Jules Verne wrote it into The Green Ray.

Cave-dwelling animals such as blind fish and pale salamanders that cannot live outside caves are called what?

Species that merely visit, such as bats that feed outside, are trogloxenes; those that can live in or out are troglophiles.

Which blind, pale European cave salamander, nicknamed the "human fish", can survive up to ten years without eating?

Locals once took the creatures washed out by floods for a dragon's offspring; an average adult lives about 68 years.

The Cave of Altamira, the first cave whose paintings were recognised as prehistoric, is in which country?

The bison on its Polychrome Ceiling now form the tourism logo of Cantabria; the man who publicised them was accused of forgery.

The word "karst", for landscapes of sinkholes and underground drainage, is associated with a plateau in which country?

Postojna Cave there has run a tourist train since 1872 and only 5 of its 24 kilometres are open to the public.

What are the mineral formations inside caves, from stalactites to flowstone, collectively called?

Almost all are calcite or aragonite; their growth layers can be read like tree rings as records of past climate.

Lechuguilla Cave and Carlsbad Cavern in New Mexico were carved from below by what, formed from gas rising off oil deposits?

Most caves are dissolved from above by rainwater; here hydrogen sulfide mixed with groundwater and ate upward.

Kazumura Cave on the slopes of Kīlauea in Hawaii is the world's longest and deepest example of what kind of cave?

It runs about 65 kilometres and drops 1,100 metres inside a flow that erupted around 500 years ago.

The Cave of the Crystals beneath the Naica mine in Mexico holds beams up to 11 metres long of which mineral?

The air reaches 58 °C with near-total humidity, so unprotected visitors can last only minutes.

The Sarawak Chamber, the largest cave room by area, lies in Gunung Mulu National Park on which island?

Three visiting cavers found it in 1981 and reckoned it three times the size of Carlsbad's Big Room, then thought the world's largest.

Which painted site in the Ardèche, discovered in 1994 and decorated around 32,000 years ago, is the subject of Werner Herzog's 3D film "Cave of Forgotten Dreams"?

Herzog got six four-hour shooting days from the French culture ministry; the public is never admitted.

Cueva de las Manos, a UNESCO site covered in stencilled hands up to 9,000 years old, is in which country?

The artists sprayed paint through bone pipes; radiocarbon dates on those pipes helped date the work.

The two known caves deeper than 2,000 metres, Krubera and Veryovkina, are both in which mountain range?

They lie in Abkhazia; Krubera is also called Voronya, "crows' cave", after the birds nesting in its entrance pit.

Rising Star Cave in South Africa's Cradle of Humankind yielded fossils of which hominin species, announced in 2015?

The route to the fossil chamber includes "Superman's Crawl", passable only with one arm stretched ahead.

Derinkuyu, an underground city carved into soft volcanic tuff and able to shelter 20,000 people, is in which region of Turkey?

Its name means "deep well", after the shafts that supplied water; the whole complex could be sealed from inside with rolling stone doors.

The Wookey Hole caves in Somerset are used by a local dairy to mature which food?

The caves hold a steady 11 °C; the same show cave houses a human-shaped rock formation known as the Witch of Wookey.

Movile Cave in Romania, sealed off for 5.5 million years, hosts an ecosystem based entirely on what?

Its air is rich in hydrogen sulfide and carbon dioxide and poor in oxygen; only a handful of researchers are ever allowed in.

The Jenolan Caves west of Sydney claim what world record?

The network follows an underground river and has over 300 entrances, still being explored.

Cenotes, the water-filled sinkholes used by the Maya for water and sacrifice, are concentrated on which peninsula?

A dense ring of them traces the buried rim of the Chicxulub impact crater.

Cave bears, which died out around 24,000 years ago, differed from brown bears mainly in what way?

Their bones were first described in 1774, when scholars thought they might be dragons or unicorns.

The Eisriesenwelt near Salzburg, Austria, is the largest example of what?

The name means World of the Ice Giants; only the first kilometre of its 42 is iced, formed by snowmelt freezing inside.

The Cave of Swallows, an open-air pit in Mexico, holds what record?

The freefall from the lip to the floor is 333 metres on the low side and 370 on the high side.

Gough's Cave, where the UK's oldest complete human skeleton was found in 1903, opens onto which Somerset landform?

The gorge's river now runs underground and only surfaces at the cave mouth.

Puerto Princesa's underground river, voted one of the New 7 Wonders of Nature in 2012, flows beneath which Philippine island?

In 2010 explorers found the river has a second storey with small waterfalls and a 300-metre dome.

The Batu Caves near Kuala Lumpur, with a 43-metre statue at the foot of the steps, are the focus of which Hindu festival?

The statue is of Murugan; Chinese settlers dug guano from the caves in the 1860s before the temple was built.

Ruby Falls, an 85-foot waterfall reached by elevator inside a cave, is under Lookout Mountain in which city?

The cave had no natural entrance; developers linked it to a neighbouring cave to create the tourist attraction.

The largest known cave room by volume, the Miao Room, is in which country?

It edges out Malaysia's Sarawak Chamber, which remains the largest by floor area.

Roughly how deep below the surface can any cave exist before the weight of overlying rock crushes it shut?

That limit is vertical depth beneath the ground; a cave's measured depth from entrance to lowest point can be less constrained.

Which speleothem grows in curling, gravity-defying shapes thanks to capillary forces, and is so fragile it is kept out of arm's reach in show caves?

Timpanogos Cave in Utah has one of the largest collections; forms have been nicknamed butterflies, curly-fries and clumps of worms.

Cave pearls form when dripping water is too turbulent to build an ordinary dripstone. What gives them their polished sheen?

A grain of sand or grit is the nucleus; despite the name they have no monetary value at all.

The first cave ever descended below 1,000 metres was Gouffre Berger, in which country?

The deepest single vertical shaft, by contrast, is the 603-metre Vrtoglavica.

Which enslaved guide mapped and named many features of the world's longest cave in the 1840s and 1850s?

His maps were among the first extensive charts of the system, which developed in rock about 330 million years old.

Which teenager explored Carlsbad Cavern with a homemade wire ladder in 1898 and named its Big Room?

The Big Room, nearly 1,220 metres long, is the largest chamber in North America and 32nd in the world.

Sistema Sac Actun, an underwater cave near Tulum, yielded the remains of which Ice Age animal alongside possibly the oldest human in the Americas?

Its name is Yucatec Maya for "white cave"; a 2018 link to Dos Ojos briefly made it the longest known underwater system.

The Jeita Grotto, home to the world's largest known stalactite, supplies drinking water to more than a million people in which country?

The lower cave can only be visited by boat; the upper galleries were found in 1958, sixty metres above it.

The Reed Flute Cave, lit in lurid colours and inscribed with Tang-dynasty poems, is a landmark of which Chinese city?

Refugees fleeing Japanese troops rediscovered it in the 1940s; one giant formation is said to be the Monkey King's magic spear.

Which grotto near Mecca is revered by Muslims as the place where Muhammad received his first revelation of the Quran?

It sits on Jabal al-Nour, the Mountain of Light, reached by roughly 1,750 steps.

The Cave of the Apocalypse, where St John is said to have received the visions of Revelation, is on which Greek island?

UNESCO listed it in 1999 together with the island's Monastery of Saint John the Theologian.

Which former Thai Navy SEAL died delivering air tanks during the 2018 Tham Luang rescue?

He ran out of air returning through the flooded passages on the night of 5 July.

The Cango Caves near Oudtshoorn, South Africa, were rediscovered in 1780 by a farmer who was lowered into a chamber that now bears his name. Who was he?

That first hall is as long as a football field; only a quarter of the 4-kilometre system is open to visitors.

Ellison's Cave in Georgia contains Fantastic Pit, one of the deepest pits in the United States. Roughly how deep is it?

Its neighbour across the cave, Incredible Pit, drops another 440 feet.

The largest chamber in any show cave, the Salle de la Verna, is in which mountain range?

It is far smaller than the wild record-holders in Asia, but you can walk in.

The highest surveyed cave in the world, Qaqa Mach'ay, sits at nearly 5,000 metres in which mountains?

Later GPS readings suggest even that altitude is understated.

The Sarawak Chamber was discovered in January 1981 by three cavers from which country?

Andy Eavis, Dave Checkley and Tony White found it during the Mulu '80 expedition; laser scanning in 2011 confirmed its size.

Sof Omar, sacred to Muslims and to Oromo traditional religion, is the longest cave in which country?

The Weyib River sinks at one entrance and reappears a kilometre away; when surveyed in 1972 it was Africa's longest.

The Longyou Caves, 24 huge hand-carved sandstone chambers of unknown origin, were found in 1992 by farmers doing what?

Five ponds turned out to be flooded caverns more than 2,000 years old, unmentioned in any historical record.

What term do speleologists reserve for a hollow formed within moving ice, as opposed to a rock cavern that holds year-round ice?

A bedrock cavern that keeps year-round ice gets the other, often misapplied, name.

Kartchner Caverns in Arizona was found in 1974 by two local cavers. What led them to it?

Cavers Gary Tenen and Randy Tufts followed the airflow; the formations inside have been growing for 50,000 years and still are.

The longest surveyed underwater cave, Sistema Ox Bel Ha, lies in which Mexican region?

At 524 km of passage it ranks second overall behind Kentucky's Mammoth Cave.