The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

A pocket of jungle amidst urban expansion in Panama.

A huge, bustling local market in Panama City.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Tiny memorials honor individual victims of the Holocaust.

This Victorian-era public house has set the standard for pub-style elegance for over a hundred years.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

An underground city of salt.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

Warsaw's fantastically preserved gasworks...almost.

The oldest housing complex in Riga is a mini timeline of architectural trends.

The Guardian of Tallinn.

The most famous location in China was home to whole dynasties worth of imperial rulers.

This smaller cousin of the Forbidden City has gone from ancestral sacrifice to tourist's whispers.

The embalmed remains of the communist leader lie within a custom crystal coffin.

The notorious "Hanoi Hilton" where Vietnamese colonial subjects and later American POWs, including John McCain, were imprisoned.

Ho Chi Minh's perfectly preserved body has been on display here since 1975.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

A nightmare for the claustrophobic lies hidden in Southeast Asia.

The deepest metro station in the world.