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.

The rusting remains are visible sticking out of the waters of the Delaware Bay.

This church in Pittsburgh is home to the largest collection of religious relics in North America.

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

Pennsylvania's own Roswell-style UFO mystery.

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

Beyond the usual stories that attend old prisons, this one has deep bloody undercurrents.

The fairy tale castle of the "fairy-tale king."

The prototype for all Nazi concentration camps.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

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

Hear the quietest sound from across the dome.

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

A mysterious castle built as a monument to lost love.

Former villa and estate of James Deering developed to preserve native tropical forests.

"We Seceded Where Others Failed."

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A monument celebrating the idea of reaching inaccessible places.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Nature's biggest mammal swims in landlocked Oklahoma.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

See massive fossils that are over 200 million years old in northeastern Arizona.