وادي النطرون
The original school in Alexandria continued until it was closed by the Byzantine emperor at the Council of Chalcedon. The centre of learning of the Coptic Church became the Monastery of Saint Macarius the Great in the Wadi El Natrun ("valley of soda-ash") 90 km north of Cairo. In 1893 the Theological College in Alexandria was re-founded by teaching children in some Cairo churches and Coptic School halls, and today has campuses in Cairo, Sydney, New Jersey and Los Angeles.