Tall columns of volcanic basalt make up this improbable-seeming rock formation.

This enigmatic building features numerous architectural styles.

A decaying, yet still functioning, work of communist architecture.

This picturesque monastery at the base of a cliff is a peaceful oasis open to all visitors.

Isak Heartstone, a 15-foot wooden troll made out of recycled materials.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

When it was built in 1929, this historic bridge was the only place to cross the Colorado River for 600 miles.

This abandoned fortress still stands guard over the Guadiana River despite a history of warfare.

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

One of the most extensive and well-preserved collections of dinosaur footprints in North America.

An abandoned sawmill from more than 134 years ago stands testament to the ambition of one man.

This theatre and its amazing marquee harken back to the Golden Age of Hollywood.

One Portuguese poet described this cape, the westernmost point in mainland Europe, as "where the land ends and the sea begins."

This impressive castle looms over small German town.

Wandering this ancient burial place offers a glimpse of the afterlife in the fresco-adorned tombs of an ancient Etruscan civilization.

A road that winds through this natural cave is the only way to access the small, appropriately-named village of Cuevas.

This remote location of this Moorish stronghold means it doesn’t attract many tourists—and that it still has the aura of fear and bravery of the 1300s.

This massive statue is the personification of Bavaria and the first colossal statue of the modern period composed of bronze.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

This house certainly has a unique decor.

Take a self-guided tour through one of Colorado's most elevated mining districts.

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

A glimpse of a waterfall is reached by a steel catwalk along a slot canyon located in an Ouray city park.