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

This beloved marketplace mascot poops money and grants good luck.

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

A daily replay of the experiment that proved the rotation of the Earth.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

Dr Barnes' $25 billion private collection of art and arboretum.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

The celebrated eyesore created by starry-eyed sweethearts.

Former hunting lodge of a duke who was an avid collector of impressionist works.

Paris' linguistic guide to the international language of, yes, love.

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

Edinburgh's oldest statue hides within a parking lot behind the city's iconic cathedral.

The dance of this huge clock is a magnificent and eerie commentary on good and evil in the history of humankind.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.

A beautiful Greco-Roman structure houses a well once believed to have healing powers.

The final resting place of soldiers' loyal canine companions.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

Protecting the dead from opportunistic body snatchers.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

The most loyal of little dogs, or a Victorian era publicity stunt?

A sweet symbol marks the place where torturous executions were once carried out.