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

An enchanting natural wonder in Puerto Rico's Camuy River Park.

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

This former railroad bridge was named after the great river that once flowed below it.

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

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

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

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

Invading U.S. troops were first seen from this now-abandoned tower, leading to the Spanish-American War.

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

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

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

The highest peak in Puerto Rico is home to a rare fern that can only be found on six trees at its summit.

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

This ''hidden'' 19th-century bridge played a simple, yet important role during the Spanish-American War.

This nearly abandoned "company town" is a ghost of Puerto Rico's once-lucrative sugar industry.

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

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

This tiny home was originally a narrow alleyway.

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

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

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

The bat-covered home of one of the world's most popular brands of rum is located on a tropical Art Deco campus.

Puerto Rico's oldest rum producer started its 140-year-old business with "a little barrel."