Sumela Monastery, also known as the Monastery of the Virgin Mary, is a Greek Orthodox monastery located in the Macka district of Trabzon, Turkey. It was founded in AD 386 and is situated on the steep cliffs of the Altindere Valley, overlooking the surrounding landscape.

The monastery is named after the Greek word "melas", meaning black, which is derived from the dark color of the rocks in the area. The main attraction of the monastery is the cave chapel dedicated to the Virgin Mary, which is located on the rock face behind the monastery. The cave is reached by a long and steep staircase carved into the cliff.

The Sumela Monastery is considered one of the most important cultural and historical sites in Turkey. It has undergone numerous renovations and restorations over the centuries, and the current structure is a mix of Byzantine, Georgian, and Ottoman architectural styles. The complex includes several chapels, kitchens, living quarters, a library, and a sacred spring.

The monastery was abandoned in 1923 due to the population exchange between Greece and Turkey. In 2010, it was reopened to visitors after a seven-year restoration project. Today, the Sumela Monastery attracts thousands of visitors every year and is a popular destination for tourists and pilgrims alike.