This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

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

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

New York City's smallest piece of private property.

Tucked in the back of this amazing antique store is an important piece of medical history.

A terrific purveyor of natural history objects and curios.

These azure waters were thought to lead to the Mayan Underworld.

Every equinox this Maya pyramid puts on a spooky ancient light show.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

This museum houses an imposing skeleton army comprised of creatures great and small.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

Stroll through retro Paris while shopping for old postcards and discarded doll heads.

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

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

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

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

This elaborate hole in the ground was built as a sacred site for an ancient civilization.

Marking the spot where a conquistador gave up his search for the fabled Seven Cities of Gold.

This Italianate Villa-style castle is pretty to look at, just keep off the private property.