The world's most active stratovolcano is almost always erupting.

Italian cave with exceptional acoustics and an unsavory history.

What looks like a link in Gondor's early warning system is actually a centuries-old Italian fortress.

Geometry and mystery come together in an epic show of octagonal masonry.

Ancient snack bar of the Roman Empire re-opened.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Erotic art covers the walls of the largest ancient pleasure palace.

The Emperor Tiberius' palace of debauchery.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

This tin chapel was built by POW's during World War II and is painted to look like something much more grand.

This Scottish burial tomb once held hundreds of ancient eagle bones.

Thanks to both terrific preservation and historic vandalism this ancient site is known as the "Heart of Neolithic Orkney."

Possibly the oldest of Britain's ancient henges is also one of its most stark.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

Famously misunderstood wonder of the ancient world

The oldest working mechanical clock in the world.