This splendid Versailles-inspired mansion has the largest French-style formal gardens in North America.

This weeping, 10-foot-tall sculpture was a maquette for a 9/11 memorial.

The rusting remains are visible sticking out of the waters of the Delaware Bay.

World War II bunker still standing on the New Jersey beach.

What began as an art installation is now the private drinkhaüs for a brewery's employees.

During World War II, this rice mill became a Nazi concentration camp.

Twisted buildings adorn the banks of the Rhine river.

Residing along a busy thoroughfare, this sculpture urges passersby to consider the future.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

A stately palace has been converted into the world's largest cannabis museum.

Week-long block party becomes a competition for the best decorated street.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

A beautiful but toxic fountain of mercury.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Cozy basement bar sports an inventory of over 2,000 beers.

A huge old mansion full of thousands of toys, each there to be used and played with.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

Meet the bronze beloved pet to a family of famous peeing statues.