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

Meant to be one of the most extravagant hotels in the world, now an eerie, abandoned architectural gem in Mexico City.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

Would you spend the night in Japan's deepest train station?

The townhouse where the "Blood Countess" Elizabeth Báthory started her murderous career.

This underground holding cell was forgotten for over a century and rediscovered in the 1960s.

The skeletal remains of the famous hominid "Lucy" were found at this spot.

The ruins of a Roman fort lie in the shadows of an imposing medieval castle.

George Martin's Caribbean recording studio now rots within the shadow of an active volcano.

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

One of the few remaining American elm trees in New York’s Tompkins Square Park was the birthplace of a new religion.

The only place where can you share a seat with the bums of the Fab Four.

More than 300,000 historical artifacts from the famous music venue, from Duke Ellington's handwritten score to The Beatles' booking slip.

What do we know about the real woman behind one of the Beatles' most famous songs?

The quiet field that inspired one of the most famous songs of all time.

The Liverpool street made famous by the Beatles is real.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

Where infamous mobster and leader of Murder Inc. Albert Anastasia made his home.

This otherwise innocuous bodega was once the headquarters of the most feared assassin's guild in American history.

An ancient city exhumed from the depths of the ocean.

The purported world's shortest international bridge connects a homeowner in Canada to his backyard in New York.

A Cold War secret surveillance tower used to spy on radio communications.

Captured in 1968, the Cold War spy ship is the only U.S. Navy vessel being held by a foreign government.

An exercise in radical design and social living that became the epicenter of Soviet spy networks in London.