An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Fantastic views and thousands of love locks.

This vast masterpiece of Moroccan architecture spreads across 20 acres.

The oldest monument in Marrakesh and the city's only surviving example of Almoravid architecture.

The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

It took 40 years to build this Eden-like garden in Marrakech, later restored by Yves Saint-Laurent.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Museum dedicated to the terror regimes of Hungary.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Unconventional site where the tracks of Zurich tramcars intersect.

One of a series of no-purpose kinetic artworks by Swiss sculptor Jean Tinguely.

Buried next to Pompeii, this lesser-known Roman villa was the opulent vacation home of Emperor Nero's wife.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

The walls and streets of the ancient city are peppered with penises.

Erotic art covers the walls of the largest ancient pleasure palace.

Ancient snack bar of the Roman Empire re-opened.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

These mechanical goats first battled it out in the year 1551, all because of an overcooked deer.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Colorful power station with a chimney equipped with a gallery for exhaust monitoring equipment.

This small Slovenian town has become a magnet for microbreweries.

A trough of 700 strange bronze faces runs through a narrow alley in Ljubljana's old town.

A whimsical bridge adorned with decorative dragons.