Hosios Loukas
Commune of Steiri, Greece · built 901
Hosios Loukas (Ὅ ᾶ) is a historic walled monastery situated near the town of Distomo, in Boeotia, Greece. Founded in the mid-10th century, the monastery is one of the most important monuments of Middle Byzantine architecture and art, and has been listed on UNESCO's World Heritage Sites since 1990, along with the monasteries of Nea Moni and Daphnion.
Monastery data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).