An unnatural lake in a naturally beautiful setting.

The location of Puerto Rico's first water bottling plant, thanks to a collaboration between Mother Nature and technology.

This memorial to a family's dead son has survived a century of hurricanes and earthquakes.

This community-driven organization uses education and eco-friendly technology to protect the environment.

This 20th-century mansion plays a key role in one of Puerto Rico's greatest novels.

The crumbling remnants of this 19th-century quarantine hospital hint at the touristy island's darker past.

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

Legend has it this historic port was a popular hideout and smuggling spot for pirates.

On a small Puerto Rican island, banks of secret naval bunkers lie abandoned and filled with piles of office equipment.

Legend tells how a Spanish soldier disappeared from this isolated sentry box without a trace.

Years of neglect and nature took a toll on this 19th-century lighthouse.

This tiny home was originally a narrow alleyway.

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

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.