Underground cities - in pictures

  • Going underground: City Hall subway station, New York. The tiled, vaulted ceilings look down on the platform which was last used on December 31, 1945. Getty Images
    Going underground: City Hall subway station, New York. The tiled, vaulted ceilings look down on the platform which was last used on December 31, 1945. Getty Images
  • The chandelier-filled cathedral carved out of the rock salt in Wieliczka salt mine, Poland, which has been on the Unesco World Heritage List since 1978. Supplied
    The chandelier-filled cathedral carved out of the rock salt in Wieliczka salt mine, Poland, which has been on the Unesco World Heritage List since 1978. Supplied
  • Religious artwork carved into the walls of the Wieliczka salt mine, including Leonardo da Vinci's 'The Last Supper'. Getty Images
    Religious artwork carved into the walls of the Wieliczka salt mine, including Leonardo da Vinci's 'The Last Supper'. Getty Images
  • Among the tunnels and chambers of the mine are many statues and sculptures carved out of salt. Getty Images
    Among the tunnels and chambers of the mine are many statues and sculptures carved out of salt. Getty Images
  • Statue of a miner sculpted from a single piece of rock salt. Getty Images
    Statue of a miner sculpted from a single piece of rock salt. Getty Images
  • Work on the underground Edinburgh Vaults was completed in 1788 and visitors can tour the many abandoned taverns and workshops. Getty Images
    Work on the underground Edinburgh Vaults was completed in 1788 and visitors can tour the many abandoned taverns and workshops. Getty Images
  • Part of the Pilsen Historical Underground tunnels in the Czech Republic, which started construction in the 13th century. Alamy
    Part of the Pilsen Historical Underground tunnels in the Czech Republic, which started construction in the 13th century. Alamy
  • The Pilsen medieval network of vaulted subterranean tunnels stretches for more than 12 miles and contains replicas of former features, such as this water wheel. Alamy
    The Pilsen medieval network of vaulted subterranean tunnels stretches for more than 12 miles and contains replicas of former features, such as this water wheel. Alamy
  • Archaeologists have found items dating back to the Middle Ages in the walls of the Pilsen Historical Underground. Alamy
    Archaeologists have found items dating back to the Middle Ages in the walls of the Pilsen Historical Underground. Alamy
  • Derinkuyu Underground City in Cappadocia, Turkey, dates back to the 7th and 8th centuries BC. Getty Images
    Derinkuyu Underground City in Cappadocia, Turkey, dates back to the 7th and 8th centuries BC. Getty Images
  • Turkey's Derinkuyu Underground City was built over 1,800 years and can accommodate over 20,000 people, including livestock and stores. Getty Images
    Turkey's Derinkuyu Underground City was built over 1,800 years and can accommodate over 20,000 people, including livestock and stores. Getty Images