Manila is strategically located on the eastern coast of the Manila Bay at the mouth of the Pasig River that runs on an east-west course through the center dividing the city into its northern and southern sectors. The City shares borders with seven other cities and municipalities in Metropolitan Manila: in the north by Navotas and Caloocan; in the northeast by Quezon City; in the east by San Juan and Mandaluyong; in the southeast by Makati; and in the south by Pasay.
The City of Manila has a land area of about 35,966,479.65 square meters based on the City Charter (Republic Act 409). The land area of Manila is expected to expand as reclamation projects are in the pipeline. However, the official city map prepared by the City Engineer’s Office estimated the total land area of Manila at 38,552,613.18 square meters, which include all reclaimed area along Manila Bay. The land area of Manila represents a mere 6.50 percent of Metro Manila’s land area of about 636 square kilometers.
Manila and the rest of the National Capital Region lie on a shelf, which has been essentially formed by a ridge of volcanic tuff to the west. Fluvial deposits of sand, gravel and clay bound the ridge. To the east of the ridge are similar deposits, transported by the Marikina River, topping a valley formed by downward and tilted fracture or fault. A good part of Manila is situated in swamps and marshes. Its proximity to the sea and major waterways makes it a strategic location for trade and commerce.
The city’s topography is relatively flat with some portions actually below the sea level so that during high tides, sea water goes about two kilometers inland along the Pasig River towards its source, the Laguna de Bay, a fresh water lake.
The physical make-up of Manila could be subdivided into two – the North Manila that is on the upper part of the Pasig River and the South Manila which is on the lower portion of the river. The Pasig River links the Manila Bay with Laguna de Bay, which has a total length of about 25 kilometers. About 2000 factories and 70,000 families in makeshift dwellings are situated along the banks of the river.