Greece, Hosios Loukas is a historic walled monastery situated near the town of Distomo, in Boeotia. It is one of the most important monuments of Middle Byzantine architecture and art and has been listed on UNESCO's World Heritage Sites
Hagia Sophia:it was built in as a Greek Orthodox Cathedral in Constantinopole (now Istanbul) by emperor Justinian.It was designed by the Greek geometers Isidore of Miletus and Anthemius of Tralles.It is considered the epitome of Byzantine architecture.
Elements of Early Christian and Byzantine Architecture
LATE BYZANTINE ARCHITECTURE - The Cathedral of Monreale, near Palermo, begun 1174 . The exterior of the apse is decorated by blind arcading of small crossed arches in arabesque style. other styles such as Norman and gothic were also used.
Monuments of Byzantine architecture. From Bilder-Atlas zum Conversations-Lexikon : Geschichte der Baukunst (plates to the history of achitecture section of the Conversations-Lexikon, AKA Brockhaus Enzyklopädie), Published by Brockhaus, Leipzig,