The Harz has a length of , stretching from the town of Seesen in the northwest to Eisleben in the east, and a width of . It occupies an area of , and is divided into the Upper Harz (Oberharz) in the northwest, which is up to 800 m high, apart from the 1,100 m high Brocken massif, and the Lower Harz (Unterharz) in the east which is up to around 400 m high and whose plateaus are capable of supporting arable farming.