Man-made and natural "dungeon" from around the world

• Man-made and natural "dungeon" from around the world

Caves and underground lakes can be called a parallel reality. For ancient people, they have become the first home, and now they are - a popular tourist attraction. They were created by nature, and to many it is difficult to reach. Underground tunnels and mine industry has created man. And this place, which is usually hidden from prying eyes. In this collection, we decided to combine all sorts of dungeons: man-made and natural, large and small - are located around the world.

This cave is located in the glacier Vatnajokull in Iceland, which is 8% of the island and is the largest glacier in Europe © legion-media

Cave in New Zealand fireflies appeared not so long ago in geological terms, a total of 12 000 years ago. The arches of the cave lit up myriads of fireflies, reflected in the waters of an underground river © legion-media

An underground swimming pool. The volcanic lake That Sua is located in the village of lotus-eaters in Samoa. The natural pool is necessary to descend to a depth of 30 meters from the ground © Mark Kolbe

Relationship underground shelter in a suburb of Aleppo © Karam Al-Masri

Billiards underground bar at Desert Cave in Australia © Mark Kolbe

The first underground park in New York. Instead of an abandoned train station in the Lower East Side residents of the city in 2020 will have recreation with real trees. While the demo opened. Special mirrors capture the sunlight from the street and through the mirror pipe system to distribute its solar panels, awnings © Mary Altaffer

Caves Son Dong, Vietnam. It opened in 1991. The biggest cave-Dong Son has dimensions greater than 5 km in length, 200 m in height and 150 m in width

Geyping Gill - the largest cave in Britain: 192 m deep and 21 km in length © Oli Scarff

Bangkok Metro. In the photo worker inspects a tunnel under the river Chao Phraya on the Mass Rapid Transit subway station © Athit Perawongmetha

4, 5-kilometer-long Canal Saint-Martin in Paris dug in 1822-1826 years for the water fountains in Paris and facilitate river traffic © Miguel Medina

Cave parastas (or "Blue Cave"), so named because of the sea seals that live inside. It is considered one of the most beautiful caves Mediterranean replete stalactites that illuminate cave reflecting sunlight. Get inside only to a small boat © Alkis Konstantinidis

Fontanelle cemetery - ossuary (ossuary), arranged in natural caves at the foot of the hill under the Materdei Naples © Cesare Abbate

Cango Caves in South Africa, called a miracle of light. They are famous for their "Organ Hall", formed by stalactites © PhotoSky

Batu Caves in Malaysia account for 400 million years. They were used by British and Chinese settlers and indigenous peoples and are considered the main shrine of Hindus outside India © Jaromir Chalabala

Construction of underground tunnel in Frankfurt © Boris Roessler

Cave Phraya Nakhon, Thailand. Attraction of the cave is the pavilion "Kuha-Karuhas" where meditating reigning monarch © Mikhail Gnatkovskiy

The Mexican city of Puebla founded around 1531. Under the city is a network of ancient tunnels © Joel Merino

The salt mine in the German town philippsthal © Thomas Lohnes

Bats in a cave in Mikulov. Almost all bats are nocturnal and sleep during the day - or hanging upside down or crouching in the trees cracks the rocks or in cracks in buildings © Radek Mica

Many enterprises Third Reich hidden under the ground - for protection from Allied bombing. In the photo corridor of one of them, near Wałbrzych, in the south-west of Poland © Kacper Pempel

Construction of the metro in Rennes, France. Rennes metro functions since March 15, 2002. It is fully automatic, driverless © Jean-Sebastien Evrard

A beautiful cave in Hebei Province in North China © Liu Huanyu | xinhua Press

Near town Ingleton in England is the biggest cave in the UK - Geyping Gill. In size it is comparable to the main cathedral of York English, who contested from the Cologne Cathedral, the title of the largest medieval church on the north of Europe © Oli Scarff

St. Petersburg Metro © Cara Anna

An underground bunker in Northern Ireland in the event of nuclear war. It is designed, however, only 235 people. Construction was completed in 1990. © Charles McQuillan