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

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

The rocks in this arid basin leave trails of movement behind them.

An underwater city for the dead.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

A dilapidated dock tells the story of Titanic's missed arrival.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.