Stunning Roman aqueduct used for 1900 years and still standing.

A Romanesque tower appears when water levels drop.

Mine shafts and hard pastries await visitors at this massive mountain of salt.

This ancient Spanish castle sits high upon a hilltop.

These striking ruins of a castle resemble a ship's stern.

An ornate tower shows off a local artist's architectural flair.

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

This whimsical winery by Antoni Gaudí looks ripped from the pages of a fairytale.

A Spanish forest is filled with mysterious stone carvings.

The Gaudí-inspired building that was the start of Terrassenc modernism.

The abandoned ruins of a beautiful medieval castle just outside Barcelona.

The unexpectedly beloved remnants of a controversial thermal power plant.

This semi-secret storybook hedge maze is also the oldest garden in the city.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

Barcelona's only remaining tram system takes riders to the Tibidabo funicular.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

An early 20th-century bullring converted into a modern shopping center.

Week-long block party becomes a competition for the best decorated street.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Bacteria and algae give the salty water its bubblegum hue.

The 20th-century church looks like a rustic version of the Sagrada Familia.

A replica of the ice houses that once formed the basis of a local ice cream industry sits proudly in the middle of traffic.