Thonis-Heracleion
An Egyptian port city near the Canopic mouth of the Nile, the country's main port for international trade in the Late Period. Weakened by earthquakes, floods and soil liquefaction, it had sunk beneath Abu Qir Bay by the end of the 8th century AD; Franck Goddio's team found it, about 6 metres under water.
Dated events and their evidence
- 550 BCE mainstream
6th-4th centuries BC: the city flourishes as Egypt's main port for international trade and the collection of taxes, around a great temple of Amun-Gereb source - 101 BCE mainstream
around 101 BC, probably after a severe flood, the ground under the central island gives way to soil liquefaction and buildings collapse into the water source - 790 CE mainstream
by the end of the 8th century AD what is left of Thonis has sunk beneath the sea, after a few residents stayed on through the Roman era and early Arab rule source - 2000 CE mainstream
a second stele is found at the temple of Heracleion, with an order of Nectanebo I to set it up in Thonis: proof that Thonis and Heracleion were one city source
Where
31.3128° N, 30.1289° E
The point is Wikipedia's position for the submerged city in Abu Qir Bay, about 7 km off the present coast.
Sources
Each event carries Aion's own evidence grade (mainstream, disputed or speculative). This page repeats what the globe shows for this place.