Heracleion

t; Coptic: Ⲧϩⲱⲛⲓ Thōni) and sometimes called Thonis-Heracleion, was an ancient Egyptian port city located near the Canopic Mouth of the Nile, about 32 km (20 mi) northeast of Alexandria on the Mediterranean Sea. 8 m (19 ft) underwater, and near Abukir. The sanctuary of Neith of Sais was located in Thonis. A stele found on the site indicates that late in its history the city was known by both its Egyptian and Greek names. The legendary beginnings of Thonis go back to as early as the 12th century BC, and it is mentioned by ancient Greek historians.

Its importance grew particularly during the waning days of the pharaohs.