Caves have been explored throughout history. In prehistory they were used for shelter, burial, or as religious sites. Today researches study caves because they can reveal details of past climatic conditions. Cavers explore them for the enjoyment of the activity or for physical exercise. For the less adventurous, a number of the most beautifulunderground caves have been converted into show caves, where artificial lighting, floors, and other aids allow the casual tourist to experience the cave with minimal inconvenience.

Eisriesenwelt Cavec

The Eisriesenwelt (German for “World of the Ice Giants”) is largest ice cave in the world, extending more than 42km (26 miles). The cave is inside the Hochkogel mountain in the Tennengebirge section of the Alps in Austria. Eisriesenwelt was formed by a river, which eroded passageways into the mountain. The ice formations in the cave were formed by thawing snow which drained into the cave and froze during winter.

Reed Flute Cave

Reed Flute Cave known as “the Palace of Natural Arts” is located in the northwest of Guilin in southern China. According to a legend, Reed Flute Cave got its name because people believed that the reed by the cave’s mouth could be made into flutes. The limestone cave offers a majestic fairyland of stalactites, stalagmites, stone pillars, stone curtains, birds, plants and animals in fantastic shapes and colors.

Cave of the Crystals

The Cave of the Crystals was discovered in 2000 by miners excavating a new tunnel for the Naica Mine in northern Mexico. The main chamber contains some of the largest natural crystals ever found in any of the underground caves around the world. The cave’s largest crystal found to date is 11 meters (36 feet) in length, 4 meters (13 feet) in diameter and 55 tons in weight. The crystals became so large because of the extremely hot temperatures inside the cave, reaching a steamy 58 degrees Celsius (136 degrees Fahrenheit), that allowed microscopic crystals to form and grow. The result is an underground cave that Superman fans have been looking for.

Puerto Princesa Underground River

The Puerto Princesa Underground River is located in a jungle covered mountain range on the northern coast of the island of Palawan in the Philippines. Until the 2007 discovery of an underground river in Mexico’s Yucatan Peninsula, the Puerto Princesa Underground River was reputed to be the world’s longest underground river and is still the longest navigable underground river. The underground river is 8.2 kilometer (5 miles) long that winds through a spectacular cave before emptying into the South China Sea.

Waitomo Caves

The Waitomo Caves are one of New Zealand’s top tourist attractions, located just outside the main Waitomo township. The underground caves are home to the famous Waitomo glowworms, tiny creatures that radiate their luminescent light. These glowworms are found exclusively in New Zealand and around the size of an average mosquito. Formed over 30 million years ago, Waitomo Glowworm Caves have majestic and ornate cave decorations, deep limestone shaft known as the Tomo and the equally magnificent Cathedral cavern known for its superb acoustics