PowerPoint Show by Andrew

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Caves and tunnels have always been part of human life. We've grown more adept at shaping these underground shelters and passages over the millennia, and today we dig for hundreds of reasons.

We excavate to find both literal and cultural treasures, digging mines, and unearthing archaeological discoveries. We use caverns for stable storage, for entertainment, and for an effective shelter from natural and man-made disasters.

And as the planet's surface becomes ever more crowded, and national borders are closed, tunnels provide pathways for our vehicles and for smugglers of every kind. Collected below are more recent subterranean scenes from around the world.

Members of the public visit the Main Chamber of Gaping Gill, the largest underground cavern in Britain naturally open to the surface, near Ingleton, England, on May 26, 2015.

An interior view of Barrikadnaya metro station in Moscow, Russia, on February 25, 2016.

A train passes through a tunnel in the rocks as people walk the foot-path “El Caminito del Rey,” or King's little path, a narrow walkway hanging and carved on the steep walls of a defile in Ardales near Malaga, Spain, on March 15, 2015.

A construction crane slowly lowers a segment of the tunnel drilling machine ‘Selina’ into the circular excavation pit to depth of 24 meters at a construction site for a new tunnel underneath the river Main in Frankfurt, Germany, on February 4, 2016.

The pool room in an underground bar in the Desert Cave Hotel in Coober Pedy, Australia, on October 22, 2015.

Skulls and bones on display in the Fontanelle cemetery in Naples, southern Italy, on November 2, 2015.

A tunnel along the Canal Saint-Martin which runs between Bastille and Republique in Paris, on July 16, 2015.

Entrance to a tunnel used by ISIS militants in the town of Sinjar, Iraq, on December 1, 2015.

People take a stroll in an underground cistern, used to hold water from rivers around the facilities to avoid floods in case of heavy rain, in Kasukabe, a suburb of Tokyo, Japan, on November 14, 2015.

Tourists swim inside the Blue Cave of the island of Kastellorizo, Greece's easternmost island, on July 30, 2015.

Overhead lights illuminate one of several recently discovered ancient tunnels underneath the city of Puebla, Mexico, on September 3, 2015.

The main conference room inside a nuclear bunker site on the Woodside Road industrial estate in Ballymena, Northern Ireland, on February 4, 2016.

This October 13, 2015 photo shows a subway station in St. Petersburg, Russia.

Visitors to the Lowline Lab inspect the plants growing under a solar canopy on February 27, 2016, in New York.

Dancers of the Friedrichstadt-Palast from the show “THE WYLD” pose on the platform of an underground train station in Berlin, Germany, on June 23.

A tunnel with tracks for mining cars, part of the Nazi Germany “Riese” construction project, pictured near an area where a Nazi train is believed to be, in Walim near Walbrzych southwestern Poland, on August 31, 2015.

Tourists visit in a limestone cave in Xinglong County of north China's Hebei Province, on November 28, 2015.

A construction worker stands inside a tunnel under the Chao Phraya river at a Mass Rapid Transit subway station in Bangkok, Thailand, on December 14, 2015.

Tourists visit a coal mine re-purposed as a tourist attraction at Gutuo Village on January 6, 2016 in Handan, Hebei Province, China.

The salt storeroom at the K+S mine in Philippsthal (Werra), Germany, on August 29, 2015.

Abu Amer (center), a former well driller, sits with family members inside their underground shelter in an Aleppo's southern suburb on October 29, 2015.

An employee drives inside a tunnel of the construction site of a metro line in Rennes, France, on October 23, 2015.

A Greek Orthodox monk prepares breakfast at Our Lady of Hamatoura Monastery in northern Lebanon on March 8, 2016.

Pakistani children sit in a cave where they live with their families in Hasan Abdal, on February 4, 2016.

A member of the public is winched to the surface after visiting the Main Chamber of Gaping Gill, the largest underground cavern in Britain naturally open to the surface, near Ingleton, England on May 26, 2015.