Safed (Hebrew: צְפַת, Tzfat; Arabic: صفد, Ṣafad, Ashkenazi: Tzfas; Biblical: Ṣ'fath, ISO 259-3: ) is a city in the Northern District of Israel. Located at an elevation of 900 metres (2,953 ft), Safed is the highest city in the Galilee and in Israel. Due to its high elevation, Safed experiences warm summers and cold, often snowy, winters. Since the 16th century, Safed has been considered one of Judaism's Four Holy Cities, along with Jerusalem, Hebron and Tiberias; since that time, the city has remained a center of Kabbalah, also known as Jewish mysticism.