Earth's rocky history has rarely glittered so brightly as it does in this Spanish museum.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

When this former hospital pharmacy closed in 2013 it already looked like a museum, so they turned it into one.

Ancient catacombs form the foundation for this Rococo orgy of a church.

Elaborate tile work in this railway station tells the story of Portugal.

A hidden three-foot-wide house separates these two regal churches.

The stunning interior of this Gothic church is covered in ornate gold details.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

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

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

Thanks to an acoustic anomaly, this unassuming stone bench has heard one hundred years of secrets.

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

This Gothic church houses ornate royal tombs and a magnificent gilded altarpiece.

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

This remarkable museum sprung from one of the most important prehistoric archaeological sites in the world.

The site of a legendary battle immortalized in medieval literature.

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

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Rare karst landscape eroded from a flat seabed.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

An interesting look into 18th-century American history.

Despite its grandiose name, this enigmatic first-century void under the town is no cave, and it's possibly not a palace either.

The extensive relics of an ancient Roman and Phoenician fish processing plant hide in a town park.

Touching this little fossil embedded in the wall of a grand mosque-cathedral may make your wishes come true.