Some mysteries may never be solved—but others are begging to be! Explore nine ancient enigmas in this episode of History Countdown.

From Egypt to Greece, explore different solutions throughout history for constructing giant structures like obelisks and temples.

The death of one of history's most enigmatic rulers—Egypt's King Tutankhamun—remains shrouded in mystery 3,300 years later.

Rising from the sands of the Egyptian desert is one of the ancient world's greatest wonders—the mighty Sphinx.