Divers discovered the rare remnants of a military vessel in the ancient drowned city of Thônis-Heracleion—once Egypt’s largest Mediterranean port—and a funerary complex indicating the presence of Greek merchants, Egypt announced on Monday, July 19.

The city, which dominated the area for decades until Alexander the Great founded Alexandria nearby at the mouth of a western branch of the Nile in 331 BC, controlled the entrance to Egypt at the mouth of a western branch of the Nile, Reuters reported.

Thônis-Heracleion was recovered in 2001 in Abu Qir Bay near Alexandria, Egypt’s second-largest city, after being destroyed and drowned along with a vast section of the Nile delta by many earthquakes and tidal waves.

“An Egyptian-French mission … found the debris of a military vessel from the Ptolemaic era and the remains of a Greek funerary complex dating to the fourth century BC,” the antiquities ministry said, according to the AFP.

According to preliminary studies, the flat-bottomed watercraft with huge oars, mast, and sails was frequently utilized for travel within the Nile Delta.

The ship that was meant to land near Amun Temple in the vicinity perished, according to archaeologists, after the legendary ancient temple collapsed in an earthquake in the second century BC.

“Finds of fast ships from this age are extremely rare,” according to the mission’s leader, Franck Goddio of the European Institute for Underwater Archaeology (IEASM).

According to the mission, the remnants of a vast Greek funeral temple complex dating back to the earliest years of the 4th century BC were discovered in another part of the city.

“This discovery beautifully illustrates the presence of the Greek merchants who lived in that city,” the Greeks were allowed to settle there during the late Pharaonic dynasties, the ministry said.

“They built their own sanctuaries close to the huge temple of Amun. Those were destroyed, simultaneously and their remains are found mixed with those of the Egyptian temple.”

It went on to say that underwater, remnants of this temple complex were discovered “in excellent condition”.

The latest discoveries attest to “the ric/hness of temples in the city which now lies under Mediterranean sea water,” according to the ministry.