A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

The hallucinogenic center of the ancient world.

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

Hidden in plain sight, Sweden's official ordnance datum is now abandoned.

A king's bloodstained shirt is among the gruesome collection of artifacts displayed below Stockholm's Royal Palace.

When this 18th-century observatory's meridian was moved, it set Sweden's time back by 0.04 seconds.

A golden plaque marks the site of the mysterious unsolved assassination of the former Swedish prime minister.

This grisly exhibit houses skeletons and weapons from a devastating 14th-century clash.

The discovery of an old wall led to the creation of this fascinating museum about the city in the Middle Ages.

Although rarely used, there is still a hidden room for the royal family at the Stockholm central station.

Frequent fliers welcome in this airplane hotel.

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.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

Sweden's "good old days" painstakingly re-created in a model village.

This Stockholm light tower can be controlled by anyone with a smartphone.

The world's largest model of our planetary system.

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

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

The celebrated eyesore created by starry-eyed sweethearts.

An atmospheric, medieval-themed book store hides in a 13th-century underground space.

This emotive sculpture was originally created for the 1878 World's Fair.

The video game-themed street art first popped up in the French city.

The approximate spot where the last Grand Master of the Knights Templar was put to death.