The decaying adobe remains of an old homestead are just off the beaten path in Joshua Tree National Park.

Crumbling pink walls and murder memorials preserve the pioneer history of Joshua Tree.

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

Drift through underground caves on a tube.

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

The ruins of the first Spanish settlement in Puerto Rico.

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

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

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

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

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

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

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

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.

This apartment is a true time capsule of local life in Bulgaria during the Soviet regime.

The Grand Mall in Varna hosts one of the biggest collections of Soviet-era paraphernalia in Bulgaria.

Mysterious standing stone formations looks like a petrified forest.

Eastern Bloc nostalgia, anybody?

Outstanding, eerie frescoes and decorations fill this 19th-century monastery.

The second-largest Jewish temple in Bulgaria was deserted after World War II, seized by the communist government and then abandoned again.

An ancient Thracian city where fire rituals were practiced on the largest cult altar in Southeast Europe.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.