Subterranean Sites

This impressive chasm is one of the longest natural underground cavities in the world.

Stuck in a bygone era, the oldest subterranean shopping street in Japan hides beneath the popular Asakusa district of Tokyo.

The largest underground pedestrian tunnel system in the U.S. mostly caters to the people working in the offices above, but provides a great, air-conditioned way to traverse the city.

Once one of the most polluted caves in America, now an environmental success story and a museum dedicated to caves.

This 300-foot-long underground tunnel was once used to transport food from the kitchen into the main building.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

The warmest cave in the Ozarks features two seemingly bottomless lakes.

How a bat poo mine became a major Native American archaeological site—and connections to legendary red-haired giants.

This underground cave located in the most barren reaches of Idaho is filled with ice year-round.

This coastal cavern is associated with the Hawaiian god of creation.

A luxurious doomsday bunker hidden beneath an unassuming Las Vegas home offers the best of subterranean suburbia.

An underground wonderland in Iowa.