The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

This cemetery features modernist statues as strange as its name.

This semi-secret storybook hedge maze is also the oldest garden in the city.

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.

Along the most northwestern point in Africa is an ancient cave surrounded by legends.

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

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

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

Macabre astrological automaton clock dating to the late 1400s.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

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

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

Yo, Adrian!

World's first "penitentiary," meant to be humane, drove men insane.