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

Traditional 11th-century outdoor tannery.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

The other side is actually green.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

Large Hadron Collider and the Birthplace of World Wide Web.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

Historic medieval fortified city in southwest France.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

This stately monument has been wearing a traffic cone hat for decades much to the delight of the locals.

A scattered trail of street art adds a pop of color to the city's stark structures.

At just 25 inches at its narrowest point, it's one of the tightest streets in the world.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.

Climb inside an iron crystal magnified 165 billion times its normal size.

This ancient theater was once the home of fierce gladiatorial battles.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

One of the world's oldest olive trees, thought to be over 2,000 years old.

On top of a resort town as old as the Bronze Age sits an incredible war memorial statue overlooking the beaches below.

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

A tiny church on a man-made island in the Adriatic.