Off the coast of Egypt, underwater archaeology has just achieved one of its most significant milestones in recent memory.
A team of specialists led by archaeologist Isabelle Hairy of the CNRS has recovered 22 large stone blocks belonging to the ancient Lighthouse of Alexandria. After seismic activity toppled the structure, its remains lay on the seafloor for roughly 1,600 years.
Project Pharos recently brought up individual blocks weighing up to 80 tons from the waters near the fort of Qaitbay.
The find provides direct physical evidence of the engineering techniques used more than 2,300 years ago — and may finally explain how a tower more than 330 feet tall was able to remain standing, unlike anything that had ever been built before.
The construction of the Lighthouse of Alexandria, begun under Ptolemy I Soter and completed by his son Ptolemy II around 280 B.C., was no isolated achievement. It was part of a deliberate effort to make Alexandria the intellectual and commercial hub of the Hellenistic world. While the lighthouse guided ships laden with grain and papyrus into port, just steps away, the city housed the greatest repository of knowledge of its age.
According to the Greek geographer Strabo and later Arab accounts, the lighthouse was not a single uniform tower. It rose in three distinct sections: a square base housing workers and supplies, an octagonal middle tier, and a cylindrical upper section where the light mechanism was installed.
The granite blocks recently recovered by Project Pharos are believed to belong to the base and ornamental elements that collapsed following earthquakes in 796, 1303, and 1323 A.D. In fact, their time underwater proved key to their preservation. Unlike monuments left exposed on land, the water protected them from weathering and looting.
What makes these pieces particularly remarkable is their sheer scale. Archaeologists are now examining the notches and anchoring systems carved into the recovered blocks. These technical details are crucial to understanding how the tower withstood multiple earthquakes before its final collapse.
The ongoing research also aims to identify the exact source of the building materials, which could shed new light on the trade and logistical networks of Ptolemaic Egypt.
Digital Reconstruction and the Preservation of Heritage
Raising the blocks is not, however, the project’s ultimate goal. Data gathered through laser scanning of the recovered pieces will be used to build a comprehensive 3D reconstruction of the lighthouse.
This digital model will allow us to visualise the structure’s true proportions, moving beyond artistic interpretations based solely on ancient written accounts and depictions on coins from the period.
The project also marks a shift in how submerged heritage in Alexandria is managed. By combining cutting-edge technology with archaeological fieldwork, a structure that no longer physically exists can once again become the subject of scientific inquiry and cultural memory.
The recovery of these remains is the first step toward documenting how natural disasters have shaped the Egyptian coastline as we know it today — and the legacy of its most enduring monuments.
