Phnom Penh lies on the western side of the Mekong River at the point where it is joined by the Sap River and divides into the Bassac River, making a meet place of four great waterways known in Cambodian as Chatomuk or 'Four Faces'. It has been central to Cambodian life since soon after the abandonment of Angkor in the mid-14th century and has been the capital since 1866.

An elegant Franco-Cambodian city of broad boulevards and Buddhist temples, it was considered one of the jewels of Southeast Asia until Cambodia became involved in the Second Indochina War in 1965. Ten years later victorious Khmer Rouge forces captured the city. These extreme left-wing communists, led by the secretive Pol Pot, ordered the immediate evacuation of Phnom Penh causing up to two million deaths during the period 1975-79. During this time the city was abandoned and fell into ruin. Since the defeat of the Khmer Rouge in 1979 it has been gradually recovering, but still bears scars of a terrible past.