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

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

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

An unnatural lake in a naturally beautiful setting.

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

This tiny home was originally a narrow alleyway.

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

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

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

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.

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

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

The world's brightest bioluminescent bay.