These abandoned salt flats are now a haven for wildlife.

An 18th-century post box used to alert the church of sick and ailing foreign pilgrims.

A 13th-century Swiss castle houses a collection of artifacts from the Polish diaspora.

A deep mark on the remains of a Roman temple, believed to be left by a legendary warrior.

The floating gallery illuminates the heart of Québec City's arts district.

Home to some of the world’s darkest skies, this project blends ancient Māori culture with world-class astro tourism.

A historic lighthouse steeped in rumors of ghost and pirate stories.

This 135-year-old weather station studied the effects of the climate on human health.

A war relic that has sat undisturbed since it crash-landed near Arno Atoll.

An early 20th-century sanatorium, long abandoned and now being reclaimed by nature.

An atmospheric, medieval-themed book store hides in a 13th-century underground space.

An overlooked tribute to one of the most important peace deals in American history.

An abandoned town is hidden in Great Smoky Mountains National Park.

A stone pillar commemorates the surrender of the extraordinary Apache leader.

A Byzantine-era church hidden in a wooded area below the Acropolis.

One of the largest lenses of its kind ever created, this former ship beacon has been brought down to Earth.

One of the few existing, fully functional Showbiz Pizza animatronic shows.

Trek through the jungle on a boat and a swinging bridge and you'll be rewarded with these refreshing, if pungent, mineral pools.

Though the original building has been demolished, these massive bronze doors were saved.

One of the few places where you can visit a cenote and Maya ruins at the same time.

This unusually shaped fortress houses a blend of centuries-old frescoes and modern art.

A semi-abandoned village destroyed by U.S. bombings during World War II dominates the valley of Turano.

This beautiful Croatian fortress is haunted by legends of forbidden love.

This breathtaking national park is one of the best places to see the weird and wonderful giant anteater in the wild.