In May 2000, Franck Goddio's team raised from the floor of Abu Qir Bay in Egypt a 1.90-meter black granite stele covered in hieroglyphs. Its inscription, identical to one preserved in the Cairo Museum, revealed the site's identity: Thonis-Heracleion, the lost city of the pharaohs, submerged for over 1,000 years. This SLICE Histoire documentary dives into the waters of Abu Qir Bay to discover the treasures of an Egypt swallowed by the sea.

Map of the Canopus, Menouthis and Heracleion region in Egypt
Map of the Canopus, Menouthis and Heracleion region in the western Nile delta -- three cities submerged in Abu Qir Bay. (Credit: Public domain, Wikimedia Commons)

Thonis-Heracleion: the city with two names

Thonis in Egyptian, Heracleion in Greek -- the same city bore two names. Located at the mouth of the Canopic branch of the Nile, it was Egypt's main entry port for ships coming from the Mediterranean. All goods destined for or coming from Egypt had to transit through it and pay duties there. Ancient texts described it as a prosperous and important city, but its exact location had been lost.

IEASM excavations since 2000 have revealed a city covering approximately 110 hectares, most of which lies under 4 to 6 meters of water and 1 to 2 meters of sediment. The site includes a great temple of Amon-Gereb (the Egyptian equivalent of Heracles), several chapels, warehouses, residences and a vast inner harbor that once sheltered hundreds of ships. More than 700 anchors and 60 shipwrecks have been found in the channel leading to the port -- witnesses to the intense maritime traffic that animated the city.

The discovery of the colossi

Among Thonis-Heracleion's most spectacular discoveries are three colossal statues in pink granite each over 5 meters tall. They represent respectively a goddess (probably Isis), a pharaohPharaohThe title of the ruler of ancient Egypt, regarded as a living god guaranteeing cosmic order (Maat), supreme head of state, army and worship.→ in traditional costume, and the god Hapy, personification of the Nile flood. Their exceptional size, remarkable state of preservation and style -- at the junction of classical Egyptian style and Hellenistic influences -- make them absolute masterpieces.

These statues likely flanked the entrance to the great temple of Amon-Gereb, whose ruins have been progressively uncovered. The temple had been built and rebuilt over several centuries, with construction phases identified from the 26th Dynasty (7th century BC) to the Ptolemaic era. Thousands of votive objects -- figurines, jewelry, vessels, coins -- were found in the basin surrounding the temple, deposited by thousands of pilgrims over the centuries.

Stele of Nectanebo I, Late Period, Egypt
Stele of Nectanebo I (380-362 BC), pharaoh founder of the 30th Dynasty, whose iconographic type is attested at Heracleion and in the Nile delta. (Credit: Public domain, Wikimedia Commons)

Canopus and Menouthis: two other submerged cities

A few kilometers northwest of Thonis-Heracleion lie the remains of two other submerged cities: Canopus and Menouthis. Canopus was a renowned cult center in Antiquity, dedicated to the god Serapis and his consort Isis. The city attracted pilgrims from across the Greek and Roman world for healing ceremonies and oracular rites. Menouthis, more modest, lay between Canopus and Heracleion.

Excavations in this area, led by Goddio and also by Jean-Yves Empereur and other teams, have yielded thousands of statues, bas-reliefs and artifacts. A large statue of Isis (probably Cleopatra VII represented as Isis) was found there, along with architectural fragments of a quality and quantity suggesting the presence of a major sanctuary. Objects from across the Mediterranean -- Rhodian ceramics, Italian amphorae, Greek tableware -- testify to the international renown of these cult sites.

How did entire cities disappear?

The disappearance of Thonis-Heracleion, Canopus and Menouthis beneath the waves is linked to a combination of geological and climatic factors. Northern Egypt's delta soil consists of fine sediments that progressively compact under the weight of constructions. Geological analyses have shown that the region experienced significant subsidence over the past millennia, worsened by episodes of soil liquefaction during earthquakes.

The devastating 365 AD earthquake and its aftershocks likely caused a sudden subsidence of several meters in certain areas. Nile flooding, increasingly frequent and violent during the early centuries AD, completed the burialBurialThe intentional deposition of a body, sometimes with offerings; a marker of symbolic behaviour.→ of the cities' low-lying districts. By the 8th century, the cities had long been abandoned, and their memory had faded to near-legend.

Stele of Ptolemy VIII Euergetes II, Ptolemaic Egypt
Stele of Ptolemy VIII Euergetes II (2nd century BC), depicted as a traditional pharaoh. Similar stelae have been found at Thonis-Heracleion and Alexandria. (Credit: Public domain, Wikimedia Commons)

The shipwrecks of Abu Qir Bay

Beyond the submerged cities, Abu Qir Bay holds another treasure: its shipwrecks. More than 60 wrecks have been identified in the vicinity of Thonis-Heracleion alone, spanning a period from the 7th century BC to the 7th century AD. These vessels -- Greek, Phoenician, Egyptian -- represented the daily traffic of a port that was Egypt's main maritime entry point.

One of the most exceptional wrecks is a 28-meter-long boat of Egyptian construction, dated to the 4th century BC. Its construction technique -- with planks assembled not by mortise and tenon as in the Greco-Roman tradition, but by wooden staples -- is typically Egyptian and rarely attested. Cargoes found in certain wrecks -- amphorae filled with wine or oil, metal ingots, crates of ceramics -- offer a striking snapshot of Mediterranean trade in the classical age.

The future of underwater archaeology in Egypt

Thirty years after Franck Goddio's first dives in Abu Qir Bay, exploration of this vast underwater territory is far from complete. Dozens of hectares remain to be excavated at Thonis-Heracleion alone, and the Canopus and Menouthis regions have only been partially explored. New technologies -- autonomous underwater vehicles (AUV), artificial intelligence for sonar data analysis, 3D photogrammetry -- open unprecedented prospects for mapping and studying these sites at large scale.

The partnership between IEASM and the Egyptian government, recently renewed, guarantees the continuation of excavations for decades to come. Each new season brings its share of discoveries -- in 2021, a ritual boat and some thirty wooden coffins were raised from the Amon-Gereb temple -- confirming that the submerged cities of Abu Qir Bay have not yet finished revealing their secrets.