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

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

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.

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

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

The ruins of the first Spanish settlement in Puerto Rico.

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

The world's last remaining store of its kind.

An elegant sandstone stairway built by the WPA still connects two neighborhoods in Akron.

For decades, this waterfall remained hidden because of an artificial dam.

Faces carved into the cliffs create an otherworldly walking trail.

The tragic reality of a town riddled with rumors of haunts, chemical spills, and serial killers.

The "mysteries" of this quintessential roadside oddity were almost destroyed by neglect but were saved by fans of kitschy wonder.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

A particularly creepy abandoned hospital that sparks interest for lovers of the supernatural.

This abandoned amusement park was built on a site with a dark history.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

Berkeley Hot Springs presents to you "the only outdoor monument to presidential bathing."

The Forest Service's surprisingly sophisticated collection of wildfire prevention art features America's most beloved bear.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

An FDR-era tuberculosis sanatorium has stood abandoned in the suburbs of the U.S. capital for over 30 years.