We all know about Alexandria, one of the greatest cities of the classical world, with its great Library and fabled Lighthouse. But Heracleion? A great port and religious centre at the mouth of the Nile, it was mentioned by the likes of Herodotus, but at some point it vanished, and its location became unknown.

"In the fading days of the pharaohs, Heracleion was the gateway to Egypt and a port beyond compare"