This hidden Art Nouveau courtyard is an opulent feast for the eyes.

2300-year-old Roman road connecting the empire.

An alchemist's "magic door" stands in the middle of a Roman park.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

This chimerical bridge/tunnel appears to dead end right into the sea.

Danish observation tower designed to look like a giant beer bottle.

The design of this beautifully crafted building was inspired by Norwegian glaciers.

This hidden green space is the city's second largest conservatory.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Frequent fliers welcome in this airplane hotel.

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

An ancient Viking runestone hidden in plain view in Stockholm's old town.

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.

Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

A unique tribute to the millions of animals who served and died for the British military.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

Hauled from the water's depths, Henry VIII's flagship is preserved in this capsule-shaped museum.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

A preserved oak tree about 3,500 years old found in Riga, Latvia.

Medical museum that houses most notably the taxidermied remains of Vladimir Demikhov's famous two-headed dog experiment.

The statue of a legendary giant who carried Christ and shouldered the world's sins.