How big is the capital of Cambodia?

Phnom Penh is the capital and the largest city of Cambodia.  It is located on the banks of the River Mekong and has been the country's capital since the French colonization.  Phnom Penh has grown to become the nation's centre of economic and industrial activities as well as the centre of security, politics, cultural heritage and diplomacy of Cambodia. 

With regards to how 'big' it is, the metropolitan area is home to over 2.2 million people and covers an area of 678.46 square kilometres (262 square miles).  Therefore the population density is 5,358 inhabitants per square kilometre (on average). The population growth rate is 3.92%.  The city has grown fourfold since 1979, and the metro area will continue to expand in order to support the city's growing population and economy.  It is certainly one of the wealthiest and most populated cities of Cambodia.

The history of the name, Phnom Penh is quite interesting:

The legend tells that a local women, Old Lady Penh was gathering firewood along the banks of the river, when she spied a floating koki tree.  She fished out the tree from the river and inside she found four Buddha statues and one Vishua.

The discovery was taken as a divine blessing, and to some that the capital was to be moved.  Lady Penh raised a small hill around the sacred objects on the west bank of the river and crowned it with a shrine.  The King of the Khmer Empire moved the capital and named it Phnom Penh. Phnom meaning hill and Penh after the founder.