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

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

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

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

Everyone from Alan Ginsberg to The Rolling Stones has stopped by this classic dive bar.

This small primate research island is teeming with playing, fighting wild monkeys.

The world's brightest bioluminescent bay.

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

On this Puerto Rican island, many abandoned naval ammunition bunkers sit open while a few have been padlocked by locals as personal storage.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

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

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

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

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

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

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

This tiny home was originally a narrow alleyway.

A magnificent waterfall nestled in the heart of the El Yunque National Forest.

The short hike is worth the stunning views and crystal blue waters of a secluded beach.

This colorful gate stands as an entrance to the walled city of Old San Juan.

This sustainable, family-run farm just outside of San Juan makes for a dreamy daytrip.

An artist’s underground sanctuary, 40 years in the making.

A park where people have been going to feed friendly pigeons since the 18th century

A place to pay homage to Taíno heritage.