Caves are underground chambers that have formed over thousands of years. While some are found at the edge of the coastline, others are formed by the erosion of waves. There are yet others that are the result of the cooling and hardening of a lava tube’s outer surface, which causes the interior molten rock to drain away. The continent of Europe boasts spectacular natural wonders, some of which happen to be the world’s most beautiful caverns. Interestingly, many of the options of the biggest cave in Europe are the result of water erosion formed in karst. They comprise spectacular formations that draw visitors to their dark interiors. With much of the cavern systems remaining unexplored, it is indeed difficult actually to zero in on which the largest cave is! That being said, we’ve compiled a list of some of the biggest and most spectacular caves on the European continent.
Table of contents
Grotte de Lombrives, France
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We begin this list with the fascinating Grotte de Lombrives in France. Shaped over millions of years, these caves lie in southwestern France at the eastern edge of the Pyrénées Ariégeoises Natural Regional Park. They’re located an hour from Toulouse and are one of the most visited sites in Ariege.
Said to have sheltered Neolithic man, the cave holds many secrets of the past. From being a burial site of a Bronze Age man to a hideout for a religious group of French protestants, there are many fascinating stories about these caves. More recently, between March and April 2021, the caves were in the public eye for the “Deep Time” experiment. It involved a group of researchers spending 40 days inside the cave to understand the link between our brains and time better.
The caves extend for about 24 mi (39 km), with passages spread over several levels. Inside there are hundreds of interesting formations to marvel at. Rock pools, stalactites, stalagmites, and calcite crystals add to the allure of exploring these caves. One of the chambers, called The Cathedral Chamber, is so huge that the Cathedral of Notre Dame can comfortably fit inside!
You can join a guided tour To explore the caves, which can last from an hour to six hours. For those not too keen on walking uphill, a train will take you to the entrance of the cave, where your guide will accompany you into “the lair of the giants.”
Gaping Gill, England
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Gaping Gill may not be the European continent’s largest cave, but it certainly is the largest underground cave chamber in Britain. Located in North Yorkshire less than two hours northwest of Leeds, this cave system is one of the longest and most complex caves in the United Kingdom. It’s so huge that someone has even tried to fly a hot air balloon inside! Gaping Gill runs for a whopping 13 mi (21 km), with a depth of 630 ft (192 m) and 21 entrances!
While it may not rank amongst the most dangerous caves in the world, it usually requires a good level of expertise to navigate. So, the cave is only accessible to experienced and well-equipped cave explorers, but twice a year, the public can explore inside. The Bradford and Craven pothole clubs set up a winch over the main shaft entrance to allow the public to descend. We’d recommend the starting point as the village of Clapham, which is easy to access from the Lake District holiday locations.
Getting to the cave is no mean feat either. It is quite a strenuous walk to the top past the Ingleborough Cave. However, the spectacular scenery is worth the walk. Once inside the cave, the roar of the waterfall can tend to drown out conversation. If you do plan to visit the cave, a good idea would be to reach it as early as possible to avoid the queue.
Škocjan Caves, Slovenia
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Featuring one of the largest subterranean chambers in the world, the Škocjan Caves in Slovenia stand out amongst the biggest caves on the European continent. These caves sit outside the town of Škocjan, an hour southwest of the capital Ljubljana. They’re surrounded by the Karst Biosphere Reserve, of which the caves are the core zone. The Reka river that rushes along the bottom of the cave has created some spectacular natural features. What’s more, the cave also has one of the world’s largest underground river canyons. The canyon itself is roughly 1.2 mi (2 km) long, up to 492 ft (150 m) high, and 394 ft (120 m) wide. Furthermore, the caves themselves have some 3.8 mi (6 km) of underground passages and a total depth of more than 650 ft (200 m).
One of the absolute highlights, or rather the standout feature here is the Martel Chamber. This gaping canyon formed by the river also showcases stunning variations of limestone bedrock. Apart from the magical visual appeal, the cave is also home to many endemic and endangered species. But that’s not all that makes this UNESCO World Heritage Site so special. Archaeological research has also revealed that the cave was once occupied by prehistoric man and was also used as a burial ground and for various rituals.
To avoid any disappointment, a good idea would be to purchase tickets in advance from the official website. Guided tours begin at the reception center, from where your guide will take you to Globočak Collapse Doline, where the entrance is. The tour takes approximately three hours and covers about 3.1 mi (5 km). However, for those who prefer something shorter, you can exit after 1.9 mi (3 km).
Fingal’s Cave, Scotland
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Fingal’s Cave might not be the largest cave on the continent, but it is certainly one of the most fascinating caves you’ll ever see. The cave sits on the Isle of Staffa lies 6 mi (10 km) west of Mull on Scotland’s western coast. These columns just above the water create a natural walkway for visitors. Rediscovered in 1772, the cave only rose to fame after renowned composer Felix Mendelssohn sent the opening phrase of an overture to his sister on a postcard. He mentioned how he had been moved by the extraordinary Fingal’s Cave. Later, artist J.M.W. Turner also immortalized the cave in his painting “Staffa, Fingal’s Cave,” arousing even more curiosity. The hexagonal columns of basalt that make up the interior walls of the cave are quite a sight, ranking them among the world’s most beautiful caves you must see.
Like many of the biggest caves in the world, Fingal’s cave has its fair share of legends. Well known to the ancient Irish and Scottish Celtic people, the cave was supposed to be the end piece of a bridge built by the Irish giant Fionn mac Cumhaill to cross into Scotland. Since the cave is very similar to the Giant’s Causeway in Ireland, the legend was believable. Interestingly, both caves have been created by an ancient lava flow and are spectacular.
This iconic cave is quite deep at around 230 ft (70 m), with an entrance that’s about 60 ft (18 m) high and 50 ft (15 m) wide. So, it’s not surprising that Fingal’s Cave has had its fair share of celebrity visits, from William Wordsworth to Queen Victoria and even “father of science fiction” Jules Verne. You can visit the cave via a boat trip between May and September.
Benagil Cave, Portugal
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In the Algarve region of southern Portugal, Benagil Caves stands out among the dozens of grottos that dot the entire coastline. What makes this cave unique is that it has a hole at the top of it, which is akin to a giant “eye!” Shaped by the pounding Atlantic waves, this cave, with its natural skylight, is worth your time. The base of the cave as well as the softer top, has been eroded to create a magical space. Meanwhile, “the eye” at the top has been fenced off to prevent accidents, you can still have a peek at the cave from the top of the cliff.
However, what actually attracts the hoards of visitors here is that within the cave sits an utterly gorgeous and pristine sandy beach. The stunning beach inside the cave is only accessible from the water, and it’s not all that difficult to find a boat that will bring you here. However, the downside to so many visitors coming here is that you won’t get to disembark from the boat and enjoy the beauty of the beach. One way to enjoy the cave while also getting in another activity is to indulge in this 2.5-hour Albufeira Tour takes you not only to Benagil Caves but even dolphin watching.
That said, kayakers and stand-up paddleboarders have access to the beach, though. If you want to avoid the rush, early morning is the best time to visit. The cave is about 650 ft (200 m) from Benagil Beach, which is where the tours begin. Most people who plan to visit the cave stay at either Lagos, Portimao, or Albufeira in the Algarve region.
Grotta Gigante, Italy
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The name itself speaks volumes about this cave, doesn’t it? We’re talking about the Grotta Gigante in Italy, which might extend for just 918 ft (280 m), but the main cavity is about 426 ft (130 m) long and 351 ft (107 m) high. Whilst this may not be the largest cave in the European continent, it is indeed one of the only caves of its size that can be visited without any special speleological equipment and training. While it was first explored in 1840, it didn’t open to the public until 1908. Even then, it wasn’t until 1957 that electricity was installed here!
Once considered the largest show cave in the world, the Grotta Gigante is another stunning Karst cave that is worth your time, with exceptionally beautiful stalagmites and stalactites adorning it. What’s more, it’s well-lit and has a good system of walkways that make it easy to explore. Since it has a constant temperature and plenty of space, it showcases scientific equipment such as two Grotta Gigante horizontal pendulums.
The specialized guided tour lasts for about an hour and allows you to explore and learn more about Grotta Gigante’s history in detail. Besides, there’s another four-hour adventure as well. From the visitor center, you will walk along a natural entrance to the first gallery, from where you’ll begin your descent. The Altar Hall is especially enchanting. While the Speleo experience is on hold, there is enough to see within the cave that will keep you hooked. The cave lies 20 minutes north of the town of Trieste.
Postojna Cave, Slovenia
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Hardly 45 minutes from the capital of Ljubljana lies the Postojna Cave system, hollowed by the Pivka River. At 15 mi (24 km) long, it is one of the largest and longest caves on the continent, the second-longest in the country, and an absolute sight to behold. Visitors can enjoy 3 mi (5 km) of the cave’s wonders on a guided tour. The best part is that almost 2 mi (3.2 km) of the tour can be covered by an electric train. Visitors are first taken to the Great Mountain cavern, where they then disembark and explore the tunnels and halls on foot.
Another interesting feature of the cave is the Russian Bridge which was built by prisoners of war in 1916. There is much that will wow you about these caves with their curious formations. The Concert Hall is the largest area within the cave. In fact, in the week between Christmas and New Year, a live Christmas Crib is displayed here. Close to the Postojna Cave is the Predjama Castle, which is known as the world’s largest cave castle.
Grotte di Frasassi, Italy
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Among the most famous show caves in Italy is the Grotte di Frasassi. Lying 5 mi (8 km) south of Genga, these spectacular caves were discovered only in 1971. However, it didn’t open to the public in 1974. With a length of 5,000 m (16,404 ft), this is one of the largest caves on the continent.
However, only a small part of the caves is open to the public. The guided tour, which lasts for about an hour-and-a-half, takes in features such as the Gran Canyon with parallel stalactites and Ancona Abyss, a cavernous 180 m-long, 200 m-high chamber. The latter is so huge it would comfortably accommodate Milan Cathedral! As with most caves that are rich in water, this cave system also has interesting stalactites and stalagmites. Paved pathways make the interiors easily accessible. Near the entrance to the caves, you’ll find two sanctuary temples, one that dates back to the 11th century.
However, it is advisable to book in advance to avoid the long queues that could form. Also, make sure you book the English tour if you don’t understand Italian. From mid-May to June, English tours depart at 11:40 am, 1:40 pm, and 3:40 pm every day, with an extra 5:15 pm tour in July and August. Outside these months, there are only Italian tours available, with English-language audio guides.
Eisriesenwelt, Austria
3
About 31 mi (50 km) south of Salzburg, you’ll find not just the biggest cave in Europe, but also the biggest ice cave in the world. We’re talking about the Eisriesenwelt Cave, a natural limestone and ice cave that extends for more than 26 mi (42 km) and has a huge footfall of visitors.
Formed by the Salzach River, the erosion of passageways into the mountain has resulted in the creation of the cave. Chilly winds blow in through the entrance of the cave, causing the snow inside to freeze. Even in summer, the ice does not melt as a cold wind from inside the cave prevents this from happening. Before the cave was explored by Anton Posselt in 1879, locals believed that it was an entrance to hell and stayed away.
Today visitors can marvel at the beautiful ice formations inside between May to October. The tour around the cave takes over an hour. However, getting to the cave requires a good level of fitness. It’s a 20-minute hike to the cable car and then another upward hike to the entrance. There are also quite a few steps within the caves.
Hölloch Caverns, Switzerland
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Sitting close to the top is Switzerland’s famous Hölloch Caverns (English: “hellhole”). Extending to as much as 124 mi (200 km) in length, it’s the 2nd-longest cave system in the European continent and the 11th-longest in the world! Not only that but also it had a depth of 3,389 ft (1,033 m), making it the world’s 4th biggest cave. First scientifically explored in 1875, it was later explored by speleology pioneer Alfred Bögli in the 1950s. As the explored length increased from 16 mi (25 km) in 1952 to 62 mi (100 km) in 1968, it became the world’s first cave to have been explored 62 mi (100 km) in length.
Naturally, there’s a basic light-filled, touristy section close to the entrance. However, the remainder is open only to qualified cavers and advanced spelunkers in the form of guided multi-day expeditions and tours. However, since it’s always 43 degrees Fahrenheit (6 degrees Celsius) in the caves, you’ll need warm clothing, no matter the time of the year. Sitting outside the town of Muotathal, these cavern systems like an hour southeast of Lucerne.
Optymistychna Caves, Ukraine
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The gypsum cave of Optymistychna (“optimistic” in Ukrainian) wears many crowns. Measuring 164 mi (264 km), it’s the longest cave system in the European continent and the world’s longest gypsum cave. Additionally, it’s the seventh-longest cave in the world! A Ukrainian natural wonder, this cave’s passages are fairly small and boast a dense, multi-level network, making it also famous known as a “maze cave”. What’s more, this massive cave complex was discovered only in 1966 by the speleologists of “Cyclope,” the Lviv speleological club. While there have been more than 50 expeditions since then, the surveys have slowed down to very little currently. Even then, they’ve managed to keep the cave in a primal state sans sidewalks or electricity. So, it’s one of the very few places on Earth to have not been fully explored.
However, they have opened a portion of the caves, around 7 routes measuring 3-18 km each (5-29 mi). They take anywhere between 3 and 14 hours to explore. Moreover, you can see huge colorful crystals, unique stalactites, stalagmites, and helictites everywhere. Since the temperature is at a steady 50 degrees Fahrenheit (10 degrees Celsius) throughout the year, guided tours of the cave are available. They provide the complete safety equipment kit, headlights, boots, hat, et al. Moreover, there’s also an experienced guide to help you all along. The best bit? The tour is offered in five languages: Ukrainian, English, Polish, Russian, and French.
These caves lie around four hours southeast of the city of Lviv.
Cool Facts About Caves
- Mammoth Cave, one of the biggest caves in the USA, is the world’s longest-known cave system at a whopping 426 mi (685.5 km)! It also has the distinction of being one of the oldest tourist attractions in North America.
- Mayans believed caves were sacred spaces, so they built temples over caves.
- The cave dwellings of Matera in Italy were once considered Italy’s disgrace due to the poverty-stricken residents who lived in them. Today, this UNESCO World Heritage Site is described as the “most outstanding, intact example of a troglodyte settlement in the Mediterranean region.”
