Saint Catherine's Monastery, officially "Sacred Monastery of the God-Trodden Mount Sinai" is an Eastern Orthodox monastery located on the Sinai Peninsula, at the mouth of a gorge at the foot of Mount Sinai, near the town of Saint Catherine, Egypt. The monastery is named after Catherine of Alexandria.
The monastery is controlled by the autonomous Church of Sinai, part of the wider Greek Orthodox Church, and is a UNESCO World Heritage Site.
Built between 548 and 565, the monastery is one of the oldest working Christian monasteries in the world. The site contains the world's oldest continually operating library, possessing many unique books including the Syriac Sinaiticus and, until 1859, the Codex Sinaiticus.