Mar Saba is a Greek Orthodox monastery located near Bethlehem, Israel and overlooks the Kidron River . It was founded by Saint Saba of Cappadocia in the year 439. While it currently houses only 10 monks, during the 7th century it held as many as 4000. It is considered to be one of the oldest inhabited monasteries in the world, and still maintains many of its traditions. One in particular is the restriction on women entering the main compound. The only building that women can enter is the Women's Tower, near the main entrance.