A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

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.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

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

This cemetery features modernist statues as strange as its name.

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

Artist Diego Morlin's war between the natural and human worlds is a wanderer's delight.

Typewriter museum housing more than 1,500 machines preserves the history of the grandfather of computers.

This Italian foot path winds through the mountains via 52 individual tunnels.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

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

Skeletons, medical artifacts, and other obscure and precious treasures all displayed in a wooden pharmacist's cabinet.

Notorious artist squat renovated into legal studios.

This bridge was constructed from the rubble of the infamous Bastille.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

This banal Parisian entranceway is not what it seems.

A mechanized clock where a man fights off a dragon, crab, and rooster.

The oldest stone house in Paris was built by its most famous alchemist.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Mining town from the late 1890s, once home to Calamity Jane.

New fungal and bacterial species call this deadly lake home.

One of the largest caves in the world open to the public.