Why it looks like this

Most of Bangladesh is flat delta, but Chattogram (Chittagong) is different: the last low ridges of the eastern hills run right through the city. Streets weave around and over the hillocks, and the port sprawls along the Karnaphuli River's north bank near its mouth.

The harbour is the reason for everything — an Indian Ocean trading port for many centuries under Arab, Portuguese, Mughal and British traders, and today the gateway for most of Bangladesh's trade.