Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

The United States Capitol's former columns still stand.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

The land is home to swimming ponies and a legendary 18th-century treasure.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

Once a mortuary that held the remains of Buffalo Bill, this Denver hotspot is now a death-fixated restaurant.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A display of magnificent stained glass windows is the first exhibit of its kind.

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

A museum dedicated to the history and exploration of both popular music and science fiction.

The last bastion of Roman presence north of the Alps looms over a German town.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

Go surfing on this urban wave, "hacked" by local surfers.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

It's good luck to be mocked by this monkey.

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

Fantastic views and thousands of love locks.

A 'living museum' in Leiden, the oldest of its kind in the Netherlands.

The attic of a four-century-old canal house hides a clandestine church.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

A floating cat sanctuary on an Amsterdam canal.