Manila Bay 

     Manila Bay is a natural harbor which serves the Port of Manila (on Luzon), in the Philippines.The bay is considered to be one of the best natural harbors in Southeast Asia and one of the finest in the world. Strategically located around the capital city of the Philippines, Manila Bay facilitated commerce and trade between the Philippines and its neighbouring countries, becoming the gateway for socio-economic development even prior to Spanish occupation. With an area of 1,994 km² (769.9 sq mi), and a coastline of 190 km (118.1 mi), Manila Bay is situated in the western part of Luzon and is bounded by Cavite and Metro Manila on the east, Bulacan and Pampanga on the north, and Bataan on the west and northwest. Manila Bay drains approximately 17,000 km² (6,563.7 sq mi) of watershed area, with the Pampanga River contributing about 49% of the freshwater influx. With an average depth of 17 m (55.8 ft), it is estimated to have a total volume of 28.9 billion cubic meters (28.9 cubic km). Entrance to the bay is 19 km (11.8 mi) wide and expands to a width of 48 km (29.8 mi). However, width of the bay varies from 22 km (13.7 mi) at its mouth and expanding to 60 km (37.3 mi) at its widest point.
The islands of Corregidor and Caballo divides the entrance into two channels,^[about 2 miles (3.2 km) towards the North and 6.5 miles (10.5 km) wide on the South side. Mariveles, in the province of Bataan, is an anchorage just inside the northern entrance and Sangley Point is the former location of Cavite Naval Base. On either side of the bay are volcanic peaks topped with tropical foliage: 40 km to the north is the Bataan Peninsula and to the south is the province of Cavite.

http://en.wikipedia.org/wiki/Manila_Bay