Caves

Since antiquity, humans have been using, living in, or hiding in caves, and our fascination with them is just as old. They connect us to our distant past because prehistoric remains and artefacts have been preserved in them, that outside would have been lost, especially in the north where Ice Age glaciers scoured everything from the surface. Our ancestors therefore had some choice over whether to venture into these places; so we today are "cave people" as much as they were.

Understand


Caves are natural underground spaces that are formed by various geological processes; they may have been adapted and modified for human use. They range from tiny recesses, to gigantic multi-mile systems such as Mammoth Cave in the United States. The forms of caves are as varied as the geological processes by which they form.

Karstic
Karstic caves are the commonest type. Slightly acidic water (through natural carbonation) dissolves limestone, marble, dolomite or gypsum. Streams then enlarge the space, carving out long tunnels. Water drips from the roof, evaporating to leave a limestone deposit, which over thousands of years builds up into a stalactite. Similar deposits grow from the ground below as stalagmites, and eventually, the two may unite into a column. This creates "decorated" caves, filled with strange natural architecture and sculpture. Above ground, the outcrops and cliffs are also curiously eroded, so karst countryside is often very scenic. Here and there it's blighted by industry, as the stone is quarried for building masonry, quicklime, cement, chemicals and scores of other uses. Karst country is found worldwide and is riddled with caves, many of which are still being explored or remain to be discovered.

Sea caves
Sea caves are carved out by wave action into fault lines, perhaps supplemented by frost. They're usually fairly short, as the power of the waves is spent within a few metres, but the larger caves are embellished by legends of pirate stash, fugitive princes and sleeping monsters. Striking examples are Fingal's Cave in Staffa, Scotland, and the "Hole in the hat" through Torghatten summit in Nordland - this is 110 m above sea level as post-glacial rebound has uplifted the region. Smoo in Sutherland, Scotland is an unusual hybrid, where a sea cave has become connected to a karstic cave.

Lava tubes
Lava tubes result from vulcanism: the outer portion of a lava flow cools, hardens and forms a sheath for the molten interior. That enables the lava to flow further, before draining away when the eruption ceases to leave a tunnel. But this depends upon a particular fluid form of lava. Volcanoes with such lava form molten lakes (caldera) at their summit, and tend to be active continuously but quietly over years, rather than having intermittent noisy eruptions. Hawaii has the best examples of these volcanoes and lava tubes.

Underground works and mines
Underground works and mines aren't covered in detail on this page, but sometimes a natural space has been extended, and if they have a natural surface they may feel more like a cave than the entrance to the Metro. Notable examples are the "Fred Flintstone" houses of Cappadocia in Turkey, the multi-coloured chambers of Petra in Jordan, the salt caverns of Wieliczka in Poland, the cellar labyrinth of Budapest, and the ice-sculpture galleries of Jungfraujoch in Switzerland.

Get in


The easiest natural underground works to access are tourist show caves, many of which have had tourist facilities installed specifically to aid access by visitors.

Viewing natural caves that are not clearly adapted or generally open for tourist visits will depend on a number of factors, such as your level of fitness and expertise, availability of local guides, and the goodwill of owners and authorities to let you enter. Obtaining the consent of landowners and the owners of the cave is vital, as is obtaining in advance any relevant official permits from governmental agencies. If you have any doubts as to your fitness, both physically and mentally, stick to 'show caves'.

More advanced 'caving' (or actual spelunking), requires detailed planning, specialist expertise as well as demanding fitness levels. It also typically requires specific technical equipment, and long-term training in the techniques used. For those that clearly understand and fully respect the risks it can be highly rewarding, but as with any extreme activity, the traveler must know the limits before embarking. Given this, detailed information is not provided here, and if you are interested, you should contact or join one of the specialist caving groups that exist.

See
Caves are numerous worldwide and only the outstanding examples can be mentioned here. For opening times, admission charges and so on see the relevant city or region page, which may also describe other caves in the vicinity.

Morocco




Argentina

 * ("Cave of Hands") in Santa Cruz province has remarkable prehistoric stencils on its walls.

Mexico
The Cenotes of the Yucatán cover a wide area of that peninsula. The limestone bedrock is riddled with caves filled with fresh or sea water, so any small pool in a forest clearing may be the entrance to a vast underground network. Cenotes played an important role in Maya religious ceremonies and may have promoted the advance of American civilization - one famous example is called "Car Wash".


 * Series of caverns inside the Sierra de Fraile mountain in northwest Monterrey. Cable car takes you to the top, the walking tour is about 2 miles long and includes several hundred steps.
 * Large cavern system operated as a national park in the state of Guerrero. Another cave, Grutas de Pacheco, is located within a few hundred meters of Grutas de Cacahuamilpa.
 * Commercial caves with waterfalls and warm thermal pools in the Central Mexico town of Ixmiquilpan. Another cave, Grutas Xoxofi is located nearby. 3 hours from Queretaro, 4 hours from Mexico City.
 * The deepest cave system in the Americas is not a commercial cave, but rather a remote wild cave for the serious cave explorer. In the town of Huautla, Oaxaca

United States

 * in Kentucky is the world's most extensive known cave system.
 * in New Mexico no longer hold the record for the world's largest cave chamber, but they're still pretty enormous.
 * are three caves in the Wasatch Range of Utah, linked by man-made tunnels.
 * in northeast Alabama is a remarkable archaeological site, with remains from several cultures going back over 10,000 years.
 * in the Shasta Cascades region of California has over 800 lava tubes, many of which can be explored, and some of which extend for more than a mile.
 * of Southern Oregon are formed in marble. That's slower to dissolve, but the chemistry and formation of dripstone decorations are the same.
 * in the Black Hills of South Dakota has over 200 miles of passages, with sparkling jewel-like calcite deposits.
 * in Texas is a rare tectonic cave, formed by shifting plates along the Balcones Fault; there are no stagmites or stalactites

China
China's Danxia landscape bears some resemblance to karst; the most famous example is at in Guangdong.


 * and – The region around these towns in Guangxi (Southwest China) is one of China's most famous and popular tourist areas, primarily because of sensational scenery. The terrain is karst limestone and includes many caves. See the city articles for details on caves that are set up for tourist visits. The area is a major destination for rock climbers, and some of the climbing shops in Yangshuo organise trips to other caves; these  all need at least basic rock-climbing skills, and some require advanced spelunking skills and equipment.

India


The following areas are considered the caving regions of India: Andhra Pradesh, Chhattisgarh, Haryana, Madhya Pradesh, Meghalaya and Uttarakhand. There are literally thousands of caves in India. There are caves that are man-made (rock cut), others which are religious sites (with or without temples), archaeological sites representing early human life and finally natural caves to explore. Those marked with the symbol are listed in the UNESCO World Heritage List.



Indonesia




Philippines
There are also many caves on Samar Island, some accessible to the general public.

Turkmenistan




Austria




Bulgaria

 * in Rabisha, north of Belogradchik, has an extensive gallery of some 750 Neolithic paintings, about 8000 to 10,000 years old.

Czech Republic

 * in South Moravia has many caves. Five that are publicly accessible are Punkevní jeskyně, Kateřinská jeskyně, Jeskyně Balcarka, Sloupsko-šošůvské jeskyně and Jeskyně Výpustek.

France

 * in the Vézère valley of Dordogne can no longer be visited, to preserve the prehistoric drawings, but they've made an exact replica.

Germany




Italy

 * on Capri is a large sea-cave. Light enters through a narrow, almost-submerged opening, so it's filtered by the sea and suffuses the chamber with a rich blue. Small rowboats can get in, but only in calm conditions at the right state of tides.
 * near Genga in Marche Region are Italy's finest show caves.

Norway

 * near Bodø is the largest natural cave in Scandinavia, and contains a glacier. It's a strenous hike and you need a guide.
 * on the Lofoten island of Moskenesøya has a cave where prehistoric paintings were discovered in 1989.
 * is a granite hill on an island near Brønnøysund in Helgeland, with a 160 m passage right through its summit. It was formed by wave and ice action.

Russia

 * in Kungur, Perm Region, is karst with ice formations within. It's Russia's only show cave.
 * in Kungur, Perm Region, is karst with ice formations within. It's Russia's only show cave.

Slovakia

 * has over 700 caves. The karst spans the border to the Aggtelek cave system of Hungary.

Slovenia

 * near Postojna is one of the largest cave systems in the world, with 20 km of underground galleries, chambers and corridors, up to 50 meters high.
 * in Triglav National Park are almost as extensive.
 * near Divača holds a huge underground canyon with its own climate.

United Kingdom
The UK has a small number of show caves.

Australia

 * near Naracoorte in South Australia have mammal fossils found nowhere else, particularly of Australian Megafauna.
 * in New South Wales are the most outstanding in Australia. These date back to 340 million years, which make them the world's oldest known cave system.
 * are within Kosciuszko National Park in New South Wales.
 * are a set of over 300 caves in Tasmania, although only two are open to the public. One has an extensive network of sediment and bone deposit, while the other is popular for its fantastic glow worm display.
 * in south-west Western Australia contains over 100 caves, some of which are open for tours. One of which; Jewel Cave contains world's longest straw in a tourist cave with impressively large stalagmites.

Photos
If you are permitted take simple photos, take them. You should however be aware that taking photos in low light will require a 'fast' sensor and/or a fast lens. Many shots in a cave will be easiest with a wide-angle lens. Seek appropriate local advice if you wish to use a flash.

Bat watching
Some caves are a habitat for bat species, and with careful planning you may be able to on the surface view the bats leaving a cave (which serves as a roost). Viewing bats leaving their roosts is best done as part of an organized group or with an experienced guide who will be able to advise on how to view without disrupting the normal pattern of the bats, who can be unduly disrupted by lights, noise or certain electronic devices.

Bats are rarely aggressive, but keep your distance since they may bite if threatened. Bats may carry rabies; anyone bitten or scratched by one should see a doctor immediately, and anyone doing a lot of caving should consider getting rabies vaccinations.

Stay safe



 * Cave canem! - Roman warning against entering the underworld, guarded by the three-headed dog Cerberus.
 * Thing is, he wasn't there to stop you getting in. But getting out again?

Even in publicly accessible caves, you need stout footwear – simply reaching the entrance may involve a hike.

A show cave has its own lighting. You need a good flashlight for others; a mobile phone light won't do to illuminate the decorations above and the perilous chasms yawning at your foot. What happens if it fails or you drop it in the stream? Carry a spare, as you value your life.

Consider the weather outlook. A downpour many miles away can suddenly turn a damp passageway into a torrent, with no place to shelter or even to breathe air. Flash floods may also scour the surface gullies that access the cave.

Don't enter a cave alone. You need someone within hollering distance who could fetch help if you came to grief. You also want somebody on the surface to raise an alarm if you got lost or trapped, at an agreed hard deadline. Let them know your detailed plan and make sure they know what they are expected to do. Mobile phones don't work underground.

Bad air is seldom a problem in natural caves, but a serious hazard in old mine workings, as the exposed coal strata continue to oxidise. This creates lethal pockets of carbon dioxide and monoxide. The weather may shift this into pools at the surface, which you'll notice when your dog (the modern canary) drops dead. Cave canem!

You must have adequate training, equipment and support to venture further than the public limits, even without plunging into the many underwater sumps. The first step is to look up the caving training agency for your part of the world. Their members often act as guides for local caves that are a bit beyond the normal public range – indeed, who else could? This gives you a chance to decide, as you wring the mud from your boiler suit and rub your bruised head and elbows, whether it's really for you.

Stay healthy
There are no particular health risks in a well-managed show cave, but actual spelunking &mdash; exploring caves that are not set up for easy visiting &mdash; does carry some risk. The main tactic for reducing it is to seek advice from knowledgeable locals; often hiring a local guide will be wise.

Bats can carry rabies and rabies vaccination is recommended for spelunkers likely to encounter bats. It is also recommended for all travellers in certain countries, and for those who will spend time in rural parts of others. Anyone planning a major trip should consult a doctor, preferably a travel medicine specialist, beforehand and rabies vaccine may be a wise precaution for many.

Animal droppings, in particular bat guano which collects in large amounts is some caves, can spread an infection called histoplasmosis; the cause is a fungus which grows in the droppings and releases spores when disturbed. In many people this infection has no ill effects, but in some cases it can be fatal if left untreated. Antifungal medications are effective against it, but it is better to avoid the infection by giving guano a wide berth.

Respect
Be respectful of the underground environment you are visiting. Ideally you should try to leave the underground environment as you found it as far as possible. No garbage and human waste should be left behind. Many flora and fauna are adapted to the underground environment, so the overuse of lights or camera flash can disrupt some fauna. The very presence of human beings and light can also severely change the micro-climate. Lampenflora – plants growing due to the light and warmth of artificial light sources – are a serious problem in some caves. Some natural caves include unique prehistoric cultural heritage (see paleontology) and care must be taken to preserve this for the future.

Touching any surface will leave organic material from your skin, and the resulting microfauna can leave handprints. Just watch beautiful or odd surfaces, leave feeling them to allowed surfaces in show caves.

Many caves are also home to bats, which in many jurisdictions are protected species, and interference with them should be avoided in nearly all circumstances. It is not unusual for caves in some regions to be closed over that region's fall and winter seasons in order to ensure that hibernating bats don't wake up too early due to human influence.

In North America the white-nose syndrome spreading between caves is a big problem. Follow advice on disinfecting your clothes and equipment. There may be other diseases or species whose spreading between cave systems should be remedied.