chalk promontory, East Riding of Yorkshire geographic county, historic county of Yorkshire, England, where the Yorkshire Wolds project 4 miles (6 km) into the North Sea. The northern cliffs, 400 feet (120 metres) in elevation, are a breeding ground for seabirds; their extremity is fretted into bays, caves, and stacks. The lighthouse at the extremity rises 214 feet above the sea.