The largest monastery on the island of Andros is the Zoodochou Pighis (meaning life giving spring), also known as "Agias".The date of its construction is unknown. Unconfirmed information suggests that the building existed and was used as a school during the Byzantine years and became a monastery in 842. There are even reports that many islanders, nobility and commoners alike, were educated here and the school produced plenty of priests, bishops and patriarchs. The monastery is officially recorded for the first time in 1400, while the chapel contains an icon dated from 1325. It was renovated during the 16th century and the 20th century and its original Byzantine form was distorted. Its celebration day is the first Friday after Greek Orthodox Easter Sunday.