This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

A subterranean display of public art and architecture.

One man's personal kunstkammer, museum and shop.

One of the most easily accessible examples of the rare 1960s UFO houses.

A stairway to heaven, or to nowhere at all.

Inside the simple black-and-white exterior of Église Sainte-Cécile hides a pastel wonderland.

Some 4,000 individual tiles make up this striking blue billboard from the golden age of air travel.

One artist's collection of homemade handicrafts doubles as a monument to 20th-century material culture.

A small Portuguese cottage formed between boulders in the countryside.

In Portugal, a secluded stretch of untouched natural beauty hides at the bottom of a steep hill.

The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.

An extravagant monument to an extravagantly unpopular Emperor.

Have fun at the world's first Buddhist waterslide park.

Twice a day a speeding train passes only inches from the homes of this residential neighborhood.

This spectacular bridge supported by two gigantic hands looks like something out of a fantasy universe.

World's largest cave was only discovered in 1991, and now offers tours to the public.

Ha Long Bay's "Cave of Surprises" houses a popular phallic rock formation.

Walk through a clothing store, across a courtyard, and up several flights of stairs for delicious coffee with a side of beautiful views.

One of the oldest temples in Ho Chi Minh City, dedicated to a deified Chinese military leader.

Life-sized painted illusions let pedestrians blend in with the street art.

One of Vietnam's most iconic landmarks was built by Japanese traders and is now in danger of sinking.

A railway station takeout shop sells boxed meals in containers shaped like trains and snowmen that hold the country’s abundant regional delicacies.