The City of Manila is situated on the eastern shore of Manila Bay, on the western edge of Luzon,  from mainland Asia. One of Manila's greatest natural resources is the protected harbor upon which it sits, regarded as the finest in all of Asia. The Pasig River flows through the middle of city, dividing it into the north and south. The overall grade of the city's central, built-up areas, is relatively consistent with the natural flatness of its overall natural geography, generally exhibiting only slight differentiation otherwise.