This incredible stone temple is a monument to death, victory, and fantasy architecture.

A century and a half of research in the sciences and natural history, still going strong.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

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

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

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.

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

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

A beautiful but toxic fountain of mercury.

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

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

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

The only museum with its curator—and her pets—buried inside.

Two stone columns flank the grand Venice square, but there were supposed to be three.

The marble facade hides a little-known medical museum with early surgical instruments and rare copies of canonical texts.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

100 year tradition of fist fights, marked by marble footsteps.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Go inside to really appreciate this 500-year-old technological masterpiece.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.