Legend says this sacred tree was a gift from goddess Athena.

An ancient Greek monument and a Byzantine church coexist inside this cave.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

Tear apart fatty, gently charred lamb chops with your bare hands.

Savor sheep milk yogurt at the last of Athens' dairy bars.

The natural mummy of the less than chivalrous Knight Kahlbutz.

This decommissioned nuclear power plant offers tours of its Communist-era control room and reactor hall.

The world's most delightful not-NOT-religion welcomes visitors to the town of Templin, just like its more stoic peers.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

One of the largest refracting telescopes in the world, and the first built specifically for studying astrophysics.

This spectrum of a star was observed by one of the world's most accurate spectrographs. 

This curious sculpture represents the perseverance needed to take to the skies.

This conical hill was built as a testing ground for an engineer known as the Glider King.

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

You've probably seen these distinctive orange-tiled columns on the big screen.

A museum in the building where Nazi Germany signed its surrender tells the story of World War II from the Soviet perspective.

Dine at a legendary after-hours joint frequented by David Bowie and Iggy Pop.

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

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

For more than 170 years, this family-run bakery has been serving Berlin’s best Baumkuchen, or “tree cake.”

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

A portable, wooden replica (minus the hyphen) of Hamburg’s iconic crooked coffee shop.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.