Top 10 caves facts

Stockholm. Many stations on the Stockholm metro use organic architecture, which leaves the bedrock exposed and unsculptured, appearing to be based on natural cave systems.

In Mexico. The cave near Naica, Mexico, was discovered in 2000 by miners. At that time, it was completely submerged. Today, the cave is accessible because the mining company's pumping operations keep it clear of water. Unfortunately, the crystals deteriorate in air, and soon may be lost.

Turkey. Through millennia, people of the villages at the heart of the Cappadocia Region have carved out houses, churches and monasteries from the soft rocks of volcanic deposits. Most of these houses have collapsed over time, but some are still inhabited.

Malaysia. Gunung Mulu national park is located in the eastern province of Sarawak, Malaysia. It is located on Borneo, near the southern border of Brunei. Gunung Mulu National Park has the largest known natural chamber or room – Sarawak Chamber. It is 700 m (2,300 ft)) long, 396 m (1,299 ft) wide and at least 70 m (230 ft) high

A kind of chemical decomposition. Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions.

Stalactites. A stalactite is a type of formation that hangs from the ceiling of caves, hot springs. A stalagmite is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings.

In caves. Roquefort is a sheep milk blue cheese from the south of France. The mold that gives Roquefort its distinctive character (Penicillium roqueforti) is found in the soil of the local caves, hence it is aged and ripened there.

In Ukraine. Optymistychna Cave (Ukrainian meaning "optimistic") is a gypsum cave located near the Ukrainian village of Korolivka. Approximately 230 km of passageways have been mapped within. As a result, it is the longest cave in Eurasia, the fifth-longest cave in the world and the longest gypsum cave in the world.

In Georgia. The deepest caves in the world are the Verevkina Cave (depth 2204 m) and the Krubera-Voronja Cave (2190 m). Both are in Georgia (Abkhazia) in the Arabica Massif.

In Chile. The Marble Caves of Chile are a series of sculpted caves in the General Carrera Lake in the heart of Patagonia. They represent a group of caverns, columns and tunnels formed in monoliths of marble. The marble walls reflect the light off the turquoise waters of the lake, creating an enchanting lightshow. The colors of the walls depend on the water levels at different times of the year.