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

The largest greenhouse in the world is home to over one million types of plants.

A open air theatre built on a cliff by an eccentric British woman.

A battle between nature and architecture in the Cambodian jungle.

Home to three historic ships from the age of Vikings.

Berlin's old airport.

Metro station with a claim to rock n' roll fame.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

Flamboyant architecture from the turn of 20th century.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

Gargantuan home of Russian science.

Thirteen sculptures in central Moscow graphically depicting vices of the modern world.

Dozens of padlock-trees along the Moscow River.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.

Moscow's imposing monument to the Space Age.

World's largest bell sits on the grounds of the Kremlin in Moscow.

Back in the tiny USSR.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

The tallest hotel in Europe.

The "Mystery and Company of Merchant Adventurers" is an Elizabethan-era hangout in Moscow.

Former headquarters of the KGB.

Stalinist skyscraper built with help of cryotechnology.

Once a bustling fishing port, this semi-ghost town is now more than 90 miles away from the shore.

Relics of Australia's convict past, and a modern scene of unimaginable horror.