Of the many Jesuit missions in South America, this complex is one of the best preserved.

At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

An English explorer's vast natural history collection has the first realistic dioramas of animals staged in their natural habitats.

This remarkably well-preserved Incan city managed to survive the conquistadores.

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

These boots are made for selfies.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

This charming railway is one of the oldest and steepest funiculars in England.

Some 10,000 works of ancient rock art cover these volcanic basalt outcrops near the Gila River.

Bacteria and algae give the salty water its bubblegum hue.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

The massive white mound and accompanying water terraces are a striking geological oddity.

Perhaps the only prehistoric monument with its very own public bus stop.

Thousands of acres of beautiful wild landscape in the Great Basin.

Thousands of Mexican Free-Tailed Bats soar around an abandoned storm drain at sunset each summer.

Part of the medieval watchtower is displayed in an otherwise ordinary parking garage.

Romania's "Red Ravine" is a little-known natural wonder that bears a resemblance to the Grand Canyon.

The medieval network of canals hidden underneath the city is opened to explorers each year.

This set of mysterious petroglyphs in the Peruvian jungle could shed light on centuries-old activities in the region.

Deep in the countryside lie the remains of one of the grandest Roman dwellings in Britain.

Where school buses go to die and be reborn as whimsical works of art.

A jungle cave in Peru of unknown depths, otherworldly sounds, and strange nocturnal birds that navigate by echolocation.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.