This bridge uses an inverted bowstring truss and is believed to be the only of its kind in the United States.

A headstone tells the sad story of a lost little boy and his pet dog.

A miniature world of concrete and stone in Springfield, Ohio.

This famous city eluded concrete detection until the early 2000's.

This column celebrates Rome's victory over the Goths, and may be the oldest Roman monument in Istanbul.

These winged Maya figures are the subject of speculation and conspiracies.

The permanent home of Elektro, the celebrity automaton of the 1939 World's Fair.

One of the most well-preserved temples of ancient Egypt.

Ancient Egyptian relief, claimed to depict an electrical light.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

Ancient snack bar of the Roman Empire re-opened.

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

The walls and streets of the ancient city are peppered with penises.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

This campus museum commemorates a national tragedy.

Memorials and tributes scattered across the university grounds remember a famous national tragedy of the Nixon era.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

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

Stone Age solar temple is aligned with the sun on each equinox and solstice.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

1513 Turkish world map, full of European state secrets and snarky commentary.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.