The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

The self-mummified monks of Japan.

A fiery crater has been burning in the Karakum Desert since 1971.

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

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

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

One of the last Jazz Age "Wonder Theaters" in New York City.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

Lie in a hammock where George Washington stood.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

Once America's longest-manned military fort, now an abandoned hulk.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

A crumbling hospital from the 1850s on Roosevelt Island.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.