Muntinglupa, municipality in the northern Philippines on the island of Luzon, in Rizal province. Part of the Manila metropolitan and the National Capital Region, Muntinglupa is located about 15 km (about 9.5 mi) south-southeast of Manila's downtown. It is bordered by Las Piñas and Parañaque on the west, Parañaque and Taguig on the north, and Laguna de Bay (the largest lake in the Philippines) on the east. The South Super Highway and the Philippine National Railways south line cross Muntinglupa from north to south. It is one of greater Manila's newer suburbs. Like many of the suburbs on the outskirts of metropolitan Manila, Muntinglupa has grown rapidly in recent years. Between 1980 and 1990 the population increased by 104 percent (compared to 34 percent for the entire National Capital Region and 26 percent for the nation). Population (1999 estimate) 488,379.