The discovery was made in the sunken ancient city of Thonis-Heracleion, seven kilometres off the Bay of Abou Qir, by a joint Egyptian-French archaeological mission
The find was announced by the European Institute for Underwater Archaeology (IEASM), which has been working at the site since its discovery by the institute’s president Franck Goddio in 2000.
The remains of the Amun temple comprise huge blocks of stone which are believed to have collapsed during a cataclysmic event dated by the team to the mid-second century BC.
Precious items belonging to the temple’s treasury were found, including silver ritual instruments, gold jewellery and alabaster containers which held perfumes.
“They bear witness to the wealth of this sanctuary and the piety of the former inhabitants of the port city,” the institute said.
A few metres beneath the remains of the temple, underground structures dating to the 5th century were located, still supported by well-preserved wooden posts and beams.
The mission was aided in its discovery by new exploration technology that allowed objects buried underneath several metres of clay to be found.
“It is extremely moving to discover such delicate objects, which survived intact despite the violence and magnitude of the cataclysm,” Dr Goddio said.
A sanctuary dedicated to the Greek goddess Aphrodite was discovered at the site, where bronze and ceramic artefacts were unearthed.
The artefacts found at the Amun temple are believed to have been imported from Greece.
Thonis-Heracleion was Egypt’s largest Mediterranean port for centuries until the foundation of Alexandria in 331BC.
The city became submerged following earthquakes that caused tidal waves and land liquefaction that left 110 square kilometres of the Nile Delta underwater.
The submersion was also due, in part, to rising sea levels.
The existence of the Aphrodie sanctuary temple suggests that Greeks were allowed to relocate, live and worship in the ancient city.
Thonis-Heracleion therefore witnessed the beginning of extensive trade between ancient Egypt and Greece that lasted for millennia since both countries were powerful civilisations on the Mediterranean.
The discovery of Greek weapons at the site has also led the mission to surmise that Greek mercenaries had been stationed in the city.
“They were defending the access to the kingdom at the mouth of the Canopic Branch of the Nile. This branch was the largest and the best navigable one in antiquity,” the institute said.
Among the many treasures that have been unearthed from the sunken city since its discovery were 64 ships, 700 anchors, a trove of gold coins, statues five metres in height, and, perhaps most prominently, the remains of a huge temple to the god Amun-Gereb.