 Almost all of Manila sits on top of centuries of prehistoric alluvial deposits built by the waters of the <unk> and on some land reclaimed from Manila Bay . Manila 's land has been altered substantially by human intervention , with considerable land <unk> along the <unk> since the American colonial times . Some of the natural variations in topography have been <unk> out due to the <unk> of the city . As of 2013 , Manila has a total area of 42 @.@ 88 square kilometres ( 16 @.@ 56 sq mi ) . 
