An eerie collection of the surviving structures from a past celebration of the future.

The oldest Roman lighthouse still in use.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

Turntable anonymously received orphans, alms, and groceries.

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

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

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

The oldest giants in Catalonia are now displayed in a 14th-century Gothic church.

A 16th-century Andalusian palace.

This lucky bronze frog was gifted to Madrid by a casino.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

Its appearance in "Game of Thrones" may spur on the long-awaited restoration of this medieval shipyard.

Abandoned Nazi train station turned underground astroparticle laboratory.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

The final resting place of the great navigator, or maybe his brother.

The world's largest wooden structure.

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

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

An eerie, abandoned military base engulfed by nature and graffiti is now home to a local park.