A team of French underwater archaeologists has found a series of massive masonry blocks which they believe are the remains of the great lighthouse of Alexandria which towered 445ft above the city's harbour for a thousand years.
Built by Alexander the Great's successor as ruler of Egypt, Ptolemy I, in around 300BC at a reported cost of 700 talents of gold, the lighthouse - known as the Pharos - was the second tallest building in the ancient world. Only the Great Pyramid, at 490ft, was taller.
What made the Pharos unique was its skyscraper profile. Whereas the Great Pyramid stood on a base 670ft square, Alexandria's lighthouse had a base just 85ft square.
From the top of the Pharos shone a great lantern which was visible 40 miles out to sea. Historians have suggested that sophisticated hydraulic equipment was used to lift fuel up to the summit - and ancient chroniclers claimed that the lighthouse was also equipped with a giant mirror - perhaps some sort of lens or light amplifier.
Part of the structure collapsed in around 700AD - a millennium after it was built - and the rest succumbed to earthquakes and neglect so that nothing remained but rubble by the 14th century.
Some masonry blocks discovered by the French divers - led by archaeologist Jean-Yves Empereur of the Centre for Alexandrian Studies - are estimated to weigh 75 tons each.
Now the hunt is on for the white marble cladding of the Pharos - and the giant statue which topped the monument.
The expedition has also found the remains of what the archaeologists believe was the Great Palace of the Graeco-Egyptian Pharaohs who ruled Egypt in the centuries before the Roman conquest.Reuse content