Once America's tallest structure, now a Baltimore landmark.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

Baltimore's first skyscraper may be home to the inspiration behind pulp fiction's most celebrated bird.

With nickel-steel armor and three-inch thick bullet resistant windows, FDR's train was a rolling fortress.

St Bernard de Clairvaux Episcopal Church, better known as one of the oldest European buildings in the Western Hemisphere.

A small museum in this border city displays the contraband art that has been stolen back from smugglers.

Take Soviet nostalgia to new heights by toasting the first man in space over a full spread of Belarusian and Soviet fare.

This space age health spa looks like a supervillain's lair.

An abandoned saucer-shaped monument in the Bulgarian mountains.

Some Moscow residents once claimed the bizarre, contorted mass of metal on top of the building was used to manipulate minds.

The avant-garde design was able to bypass strict Soviet regulations on architecture.

Hidden in a metro shop under a shopping mall, this small museum tells the story of one of the world's largest urban transit systems.

This oddly shaped building is a surprising Soviet-era crematorium.

An early-20th-century "dacha" village of quaint cottages curiously located in a modern part of Moscow.

A unique Soviet mosaic preserved on the facade of a shoe factory in Lviv.

An abandoned masterpiece of Soviet Brutalist architecture.

This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

This abandoned secret city is a crumbling wonderland of Soviet ruins.

A striking Soviet memorial commemorates the liberation of Belarus from the Nazis.

Remains of the old fortification along the Western border of the USSR, now an elaborate defense museum.

In the hinterlands of Serbia's capital, a giant reflective mushroom houses an aeronautical history of the former Yugoslav republic.

A graveyard of old and rare planes that once were the glory of Persian aviation.

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

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.