A set of seven houses, each built in a style that represents a European country.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

Amsterdam's former hotspot for public executions and dissections.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This unattributed sculpture in Amsterdam is hiding in plain sight.

A beautifully eclectic mix of architectural styles.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

This 23-foot-tall bear stands amid the hustle and bustle of Hamad International Airport.

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

Depending on who you ask, this controversial treehouse is either a charmingly creative child's playhouse or an illegal encroachment on public land.

This statue of the "father of television" stands prominently in the United States Capitol.

D.C. once had its own tiny rival to the New York Stock Exchange.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

An overlooked memorial honoring the local Washington residents who died in World War I.