This Roman arena once played host to bloody gladiatorial battles.

Long tunnels run under the ancient chariot racing circuit to the tower.

Famed architect Antoni Gaudi built this generous thank you gift to a friendly host who housed him during a job.

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

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.

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

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

This Funeral Hearse Museum represents the finest in cadaver transportation.

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

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

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

Lemon Grove, California is known for its giant lemon...and mummified bodies.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

In the "Danish Capital of America," a replica of one of Copenhagen's most iconic buildings.

The oldest pictographs on this decorated rock formation in California's Carrizo Plain date back as many as 4,000 years.

The viewpoint for this attractive, off-the-beaten-path waterfall is reached by a paved, wheelchair-accessible trail.

Deep vertical fissures like miniature slot canyons cut across the cemented volcanic rock of Black Point above Mono Lake.

The American rainmaker and a burst dam.

California's longest-running tourist attraction is a stump.

Exquisite irises bloom every spring in this hillside garden.

At night, this glittering musical tunnel draws skaters and photographers.

A veteran Disney animator turned his gift for storytelling to a museum devoted to his love of a California city.