Firstly, a coffer dam was built around the temple and the water was drained. Next, the temple was dismantled and transferred, stone by stone, from the submerged Philea Island to the redesigned Egilica Island. Each and every stone had to be numbered, and then replaced, in the same position, in the new location. It was a massive, and very complicated, project taking over 9 years to be accomplished.
The Temple of Isis consists of The 1st Pylon, which is a great traditional pylon with two towers, and an open forecourt, which leads to the 2nd pylon. On the left side of this court is the Mamisi, which has scenes depicting the birth of the God Horus by his mother Isis. The 2nd Pylon leads to a Hypostyle Hall with 10 columns, and then 3 vestibules leading to a sanctuary.
The Temples of the island were neglected, and some of them even destroyed, after the persecution of the Christians by the Roman Emperors. During the reign of the Emperor Justinian (527-565 A.D), the main Temple was converted to a church.