Rift Valley, a depression in the earth's crust, formed when a block of land slips downward between two parallel, vertical faults,or fractures of the crust. The most famous rift valley is the Great Rift Valley, which extends about 3,000 miles (4,800 km) from the Sea of Galilee in Israel to Lake Nyasa in southeast Africa. Examples of smaller rift valleys are that part of the Rhine valley between the Black Forest (Germany) and the Vosges Mountains (France), and the central Lowlands of Scotland. Rift valleys are sometimes called trough faultsor graben, a German word meaning "ditches."