In modern history textbooks, the city of Thonis-Heracleion was rarely mentioned. It was a legend but also a myth. All that was known about it was that it was like an ancient Egyptian Venice and the city was exquisitely built with canals and was the mainland for trade. That it submerged into the water completely because of an Earthquake is also just a theory. Absolutely nothing was concretely known about this city until recently when it was rediscovered.