Puerto Rico's once thriving oil company is now an abandoned wonderland of rusty steel.

The abandoned remains of this once-thriving hotel looms over the city, awaiting an uncertain future.

This small fort played a huge role defending Puerto Rico’s capital city.

This giant bronze image of Christopher Columbus embarked on a voyage of its own.

These red and black houses were awarded to the firefighters who saved their city from an enormous blaze.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

This former sugarcane transport tunnel is now a portal to a lovely beach.

This niche museum devoted to ancient religious artifacts is shaped like the very thing it displays.

This limestone cave offers an incredible view of the Río Grande de Arecibo valley.

The world's second largest single-dish radio telescope, once used to contact E.T.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

A tiny islet just off Long Island offers a wealth of infectious curiosities.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

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

A temple to modernity, tucked away amid Barcelona's more well known museums.

A stately palace has been converted into the world's largest cannabis museum.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

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.

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.