This open-air heritage museum illuminates centuries of historic English life from a West Sussex village.

The oldest still-inhabited hill fort in India looks like a magnificent golden sandcastle.

One of the largest and oldest caravansaries in Persia.

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

A measuring mishap led to these artificial stone ladies losing their stomachs.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Old batteries and frog skeletons reside in this lakeside monument to Alessandro Volta.

The dramatic upward-curving roof is one of the most iconic examples of Googie architecture that still stands today.

Crumbling ruins of the thermal baths that once attracted royals and aristocrats from throughout Europe.

This monastery built into a cliff hides a perfectly preserved hermit in a glass coffin.

A once-luxurious, now abandoned hotel in the Italian Alps.

The Sighignola summit on the Swiss border offers views so breathtaking it's been named one of the most beautiful places in Italy.

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

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

The grassy landscape is home to the world's last truly wild horses.

The highest point in Virginia can only be reached by passing through ponies and flowers.

The oldest Roman lighthouse still in use.

The oldest European burial ground in Australia.

The largest land animal skull ever discovered.

A novel collection of medical curiosities housed in an 18th-century surgeon training academy.

The marble facade hides a little-known medical museum with early surgical instruments and rare copies of canonical texts.

A grotesque collection of wax limbs depicting the symptoms of venereal disease.

The "birthplace of insulin," where Sir Frederick Banting realized the hormone could save the lives of Type 1 diabetics.