The history of this Moorish castle includes royals, a Mexican-Spanish association, and several attempts at lodging.

The facade of this 16th-century building is decorated with carvings of 300 seashells.

These "mermaids" that surround a plaza in Segovia are rather sphinx-like.

Two large posteriors in one giant statue.

The fragmented remains of a massive public bath connected to the city's water supply.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

An accidental trick of light casts the perfect shadow of a pilgrim of the Camino de Santiago against the cathedral wall.

The atmospheric ruins of a historic church can be found on a hill above the city of Oviedo.

A historic Christian shrine nestled within a spectacular natural cave.

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

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

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

Unique Michigan homes look like something out of Tolkien's "The Lord of the Rings."

An angular maze of concrete in Grand Rapids acts both as public art and as a staircase for fish traveling upstream.

Strange physical sensations and optical contradictions keep visitors coming back for more.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This shallow cave got its name from copious amount of human bones found inside.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

This freshwater spring fills with 10,000 gallons of water per minute.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

A spiritual vortex among the red rocks in Sedona.

Swim or sail to this pie-slinging boat off the coast of St. Thomas.

The world's largest collection of the world's largest objects is in one small Illinois town.