There are hidden patterns on the subway seats of some Stockholm metro cars.

This small statue hints at the incorrect origins of the lush landscape park surrounding it.

This railroad track was so secretive that it was omitted from all maps.

Small Easter eggs are hidden in the ventilation holes of the city's newest trains.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

The Swedish flag over this small naval fort signals that the nation is at peace.

Outside a Viking museum sits a modern-day runestone made by a Swedish runemaster using traditional methods.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's deepest subway station is also a stunning ecological wonder.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

A beautiful gorge filled with streams and waterfalls.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

For over 40 years, this quaint little house has teetered on a rock in the middle of a river.

A grand Yugoslav memorial to the group of partisans who fought and died resisting western Serbia’s Nazi occupation.

A medieval bridge stretches over a sulfur-rich river that leads to year-round natural hot springs.

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

Climb into Albania's communist history while enjoying a spectacular ocean view.

Monasteries on rock pillars, once accessible only by frayed ropes.

Thousands of rusting train cars have been slowly falling apart on the edge of Greece's second largest city.

An autonomous republic of Orthodox monks.

This sculpture used famed boxer Joe Louis as the inspiration behind its body.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.