The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

One of the last Jazz Age "Wonder Theaters" in New York City.

A former ironworks that was the first UNESCO industrial site.

This magnificent blue mosque in Afghanistan is surrounded by thousands of white doves.

Once the fallout shelter of a dictator, this sprawling bunker is now a combined history museum and contemporary art gallery.

This series of rope-style bridges brings visitors into a jungle layer that is usually reserved for birds and monkeys.

A fiery crater has been burning in the Karakum Desert since 1971.

A city built from mud and known as the "Manhattan of the desert."

The latest in a series of long glass bridges suspended at terrifying heights.

At nearly 1,000 feet long, this astonishing glass suspension bridge is one of the longest in the world.

A striking Soviet memorial commemorates the liberation of Belarus from the Nazis.

A plaque commemorates the spot in the Oregon woods where the first-ever Geocache was hidden.

A once-luxurious, now abandoned hotel in the Italian Alps.

An architect transformed this abandoned cement factory into his castle-like workshop.

At the center of an island in the middle of the Indian Ocean is a deep chasm ringed by tall waterfalls.

No one is sure what to do with this WWII shipwreck that sits at the bottom of the Thames, still loaded with tons of explosives.

This former coal gasification plant found a curious second life as a popular public park.

A breathtaking canyon offers stunning views and frightful pathways through an ecological paradise.

This winding road through an Italian canyon may be the most scenic drive in the world.

Stunning wetlands ablaze with pink lotus flowers.

This Italian foot path winds through the mountains via 52 individual tunnels.

This Italian ski resort rose to fame when Benito Mussolini was held prisoner there and then rescued by the SS.

A climbing route in the mountains of Italy’s Dolomites, built for soldiers during World War I.

This amazing pedestrian suspension bridge in the Swiss Alps would give Indiana Jones nightmares.