lowland plain area, southwestern Norway. Extending approximately 25 miles (40 km) northward from Eigersund and 10 to 15 miles (16 to 24 km) inland from the North Sea, the plain is bounded on the southeast by the Dalane Plateau. Unlike most of the Norwegian coast, the plain is not protected by islands; instead, a dangerous reef, Jærens Rev, lies about 3 miles (5 km) offshore. Trees have been planted along the coast to prevent sand and soil erosion. The fertile soil of the plain—composed of glacial deposits of sand and clay—and the mild winters of the region make Jæren one of Norway's finest agricultural areas. Dairying is important; Jæren is the principal supplier of milk to the city of Stavanger, just to the north. The Stavanger-Sola Airport is located in the region. Excellent bathing beaches along the coast attract visitors, as do ancient burial mounds and runic inscriptions found on the plain's glacial boulders.