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

Designed by Gustave Eiffel before his famed tower.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Mountain where Jesus was first tempted by the Devil.

This cemetery features modernist statues as strange as its name.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

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

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

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

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

Artist James Turrell's ode to dawn and dusk on the campus of Rice University.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

The tomb of history's greatest potato promoter is surrounded by tubers.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

France's national museum of scientific and industrial instruments.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

The final resting place of the poets Shelley and Keats.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Rome's semi-secret peephole vista is also a former Crusader stronghold.