Ancient serpentine sacrifice holder that has stood the test of time.

A vast city of the dead, where the deceased outnumber the living by more than a million.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

A church of bones, decorated with 40,000 human skeletons.

The land is home to swimming ponies and a legendary 18th-century treasure.

The former Naval shipyard is open for exploring - mostly.

The city of Halifax still bears the scars of the largest explosion prior to the atomic bomb.

Once a favorite playground for the world's most illustrious guests, Hotel Nacional's secret weapons and bunkers reveal a more menacing side to its golden history.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

A time capsule of Floridian history fights to survive on the banks of Chokoloskee Bay.

New York's unstoppable progress turned this cemetery into the smallest burial ground in the city.

Small monoliths of several varieties of stone sit alongside a wooded path in the Bronx.

San Francisco's newly reopened hands-on science museum.

Buy your friend a drink or staple some cash to the wall for the next guy at the Salty Dawg Saloon.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

An abandoned horticulture institute gloomily presides over rows of derelict and vine-wrought greenhouses.

This dilapidated castle-like structure overlooks the Hudson River at one of its widest points and was once home to nuns.

This outpost of America's most popular fast-food restaurant is housed inside a palatial mansion.

Experience a charming 1930's version of "infotainment."

Macabre astrological automaton clock dating to the late 1400s.

This red-eyed chrome beast pays homage to the popular modern myth of West Virginia's insectoid monster.

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

A marvel of Byzantine engineering under the streets of Istanbul.