The perfectly preserved underground rooms where Churchill plotted the war against Germany.

An unusual round church in London with a Templar past.

This South London cemetery holds the remains of more than 15,000 people.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

Some say this medieval church is where the poet Dante married his wife and also met the love of his life.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

The oldest operating pharmacy in the world features 800-year-old recipes.

The famous facade of Grand Central Terminal hides a regulation tennis court—and it's not the first one.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

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

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Elevated freight railway turned wildly successful urban park.

The final resting place of the poets Shelley and Keats.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The yawning maw of this pagan visage is said to bite off the hands of liars.