This museum preserves the heyday of Puerto Rican coffee.

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

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

La Cara del Indio honors the Taíno chief who fought bravely against the Spanish invasion of Puerto Rico.

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

Drift through underground caves on a tube.

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

An unnatural lake in a naturally beautiful setting.

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

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

This beachside town is home to a diverse nature reserve, multiple cays, and one of the three bioluminescent bays in Puerto Rico.

This trio of Dominican cave lakes comprise a colorful biosphere of natural life.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

Hundreds of pieces of ancient Taíno art cover the walls of this Caribbean cave system.

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.

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

Enjoy the waters of this half-moon-shaped natural pool surrounded by breathtaking scenery.