The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

A sprawling collection of books and manuscripts about ancient Greece that would have put their famed libraries to shame.

An 11th-century runestone decorates the halls of Terminal 2 of this Scandinavian travel hub.

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

Legend has it that this large rock maze in Sweden was created as punishment by the daughter of a wealthy captain.

A catapult rock from Gotland’s 13th-century civil war is still lodged in Scandinavia's best-preserved medieval city wall.

Known locally as the Jungfrutornet, this Medieval tower hides a dark legend.

Discovered in a peat bog, these horned helms come from a thousand years before the Viking Age.

This pair of gilded girls atop an Art Deco building in Copenhagen were built to function as a weather indicator.

The only surviving piece of Copenhagen's 16th-century defensive wall.

One of Scandinavia's largest mosaics pays tribute to Danish art and science luminaries.

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

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.

Breathtaking and huge 430 year old maps of Italy.

This fortress-like monastery is covered with intricate frescoes.

The most impressive example of contemporary Romanian architecture in wood

When this 400-year-old fountain fell into disrepair, officials covered the mess up with what looks like a giant soup tureen.

This 18th-century sundial was designed to calculate the date of Easter each year.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

This massive library holds what was once the largest book collection in the world.