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

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

2300-year-old Roman road connecting the empire.

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

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

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

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

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

Love, knishes, and best wishes from this legendary Lower East Side bakery.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

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

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

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Ride the subways of yesteryear.

Elevated freight railway turned wildly successful urban park.