Home to secret Eastern Bloc spy equipment and the largest stretch of the original Berlin Wall outside of Germany.

A Rodeo for Prisoners.

Once defending the city of New Orleans from invasion by sea, this fort faces an uncertain future.

The crumbling remains of a 19th century fortess.

Barely visible foundations remain where Stow Lake’s “observatory” once welcomed visitors.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

The restored and active Victorian-era final resting place of San Francisco.

Longtime headquarters of controversial boys' club for the world's wealthiest and most powerful.

Adolph Sutro's little-known, geographically inaccurate, deprecated monument.

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

One of the oldest medical collections in Europe focusing on rare surgical instruments.

1898 German railroad depot museum with working engines, steam train excursions, and hands-on displays.

Constructed in the 1920s, this former pencil factory is now an office building.

Canada's subterranean Cold War museum has doubled as a movie set.

An alchemist's "magic door" stands in the middle of a Roman park.

The oldest bibliophilia club in America, with exhibitions on historic books and graphic arts.

Time capsule of a museum, in which the Soviet Union remains alive and kicking.

Visit the site of a subway powered by nothing more than air--and lots of it.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

This recently rediscovered Civil War-era submarine was the first to ever sink an enemy ship.

This majestic building, where Brazil's coffee brokers once bought and sold beans, now houses a coffee museum.

A good place to research the Freemasons, esoterica, occultism, and hermeticism.

Elevated freight railway turned wildly successful urban park.

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