The most elaborate of 12 medieval arched doorways to the old city of Burgos.

A Gothic cathedral created from volcanic rocks.

Historic medieval fortified city in southwest France.

These fly sculptures are scattered around the city and represent the patron saint of Girona.

A statue of a boy looks up at where the famous rival to the Leaning Tower of Pisa once stood.

Mountain where Jesus was first tempted by the Devil.

This Roman arena once played host to bloody gladiatorial battles.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

This multi-level, aqueduct-footbridge hybrid is one of the greatest works of the Spanish Renaissance.

These magnificently sculpted tombs represent Spain's own legendary version of "Romeo and Juliet."

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

This enormous censer uses a pulley system installed over 400 years ago.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

Famously misunderstood wonder of the ancient world

Huge winged monument in the United Kingdom.

The lost Latin words were reconstructed using the holes from the nails that once pinned them in place.

The ruins of a former sanctuary for elite Aztec warriors.

The stoutest tree in the world.

The tower was originally used as a chimney for the waste incinerator of St. John's Precinct and Market.

Created as a punny statement about genetic engineering this monstrous hybrid statue has become a beloved icon.