This top secret Chinese military megaproject is the world’s largest human-made tunnel structure.

Comprised of thousands of cave temple carvings this cornucopia of ancient Chinese stone art is unrivaled anywhere in the world.

Two ancient Buddhist temples crown this dramatic rocky pinnacle.

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

In a city of wooden houses, this watchtower was vital for early fire detection.

The world's northernmost botanic garden has 25 collections of plants from arctic and alpine regions.

Norway's oldest cathedral still in use.

This ratty natural history collection is a charming relic among a city rushing into modernity.

A son-and-daughter meat market, hawked by mom and dad.

An out-of-place slice of France, smack in the middle of Shanghai.

An collection of Chinese propaganda posters from 1949 to 1979.

This psychedelic tourist trap is a leisurely descent into madness.

A haunting contrast of trains that both saved and took the lives of Jewish children in Nazi Germany.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Tiny memorials honor individual victims of the Holocaust.

Cold war icon and onetime "hole" in the iron curtain.

One of downtown Berlin's last reminders of its Communist past.

Berlin's old airport.

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

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

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