Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.

An ancient Egyptian temple in the middle of Madrid, Spain.

Giant, friendly pelicans in Central London, the most unlikely of places.

A 12th century church completely covered in shells.

Italian cave with exceptional acoustics and an unsavory history.

The world's most active stratovolcano is almost always erupting.

Giant granite sculptures representing family on the northern coast of Spain.

A little sculpture with a large wardrobe.

The celebrated eyesore created by starry-eyed sweethearts.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Macabre astrological automaton clock dating to the late 1400s.

A mocking tribute to the past and modern leadership of Prague.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Mountain where Jesus was first tempted by the Devil.

Village situated on a narrow volcanic escarpment.

Go inside to really appreciate this 500-year-old technological masterpiece.

An underground city of salt.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

The remains of an encyclopedic sculpture garden later used as an internment camp.

The oldest Roman lighthouse still in use.