The Monastery of the Virgin Mary of Mavriotissa is a monastery that is built on the spot where troops of Byzantine military commander George Palaiologos encircled the attacking Normans in 1083. It is believed that the emperor Alexios I Komnenos, built the monastery there to commemorate the event. Surrounding the region of the lake of Kastoria there are 72 churches and chapels, Mavriotissa being one of the earliest of them.