Thousands of well-dressed mummies below a monastery.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

An Austrian house of bones filled with hundreds of intricately painted skulls.

A church of bones, decorated with 40,000 human skeletons.

This dizzying span over the ancient Algerian city was once the highest suspension bridge in the world.

These decaying bridges 1,000 feet high are a reminder of the skill it took to cross the Colorado Rockies by rail.