A popular legend claims that the famous pizza was invented at a restaurant in this alley.

An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.

This magical-looking island is notorious for the misfortunes suffered by its owners.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

Op-art architecture designed for happiness.

A spherical "micro-nation" in the heart of Vienna.

The topiary maze at the Habsburg hunting lodge.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

This strange statue features a bust of the famous composer plopped atop a woman's body.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

Dedicated to this region's early settlements and rich history of salt mining.

These 400-year-old ruins are all that's left of the monastery where Ines de Castro was assassinated by the King of Portugal.

A replica of the Roman emperor in glorious full color.

Nicknamed "Karri Knight," this Eucalyptus was planted in 1895 and stands at 72 meters.

This ship offers visitors the chance to spend the night aboard a former floating hospital for fishermen.

An icon of the city, this chapel features an amazing dome ceiling and offers panoramic views.

Eat the ultimate iteration of Portugal's most beloved pastry.

A deer-headed statue that brings together a 12th-century legend and big wave surfing.

This historic streetcar system has been running since the 19th-century.

The "Little Ones," show Portugal in full miniature splendor.

A fortress off the West coast of Portugal that dates back to 1502.