The world's largest reflecting pool is just two centimeters deep.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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.

A striking symbol of the Bulgarian capital.

A magnificent, glittering building tucked into a tiny Bulgarian mountain town.

An abandoned saucer-shaped monument in the Bulgarian mountains.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

This outdoor gallery of graffiti-covered walls pays homage to the past, present, and possible future of street art.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

Elevated freight railway turned wildly successful urban park.

Try not to get slimed in Tribeca.

This demon atop the Notre-Dame de Paris looks utterly bored.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

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

These engineering masterpieces are a dominant feature of the Belfast skyline.

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

San Gennaro, the patron saint of Naples, greets pedestrians between these narrow city streets.

Destroyed numerous times, this centuries-old bridge has always been rebuilt with its original design.

A mysterious ancient elephant said to possess magic powers is now the symbol of a Sicilian city.

A military museum, art park, mausoleum, and architectural oddity all on one fascist's estate.