The road system in Zambia is extremely simple. There are only a few major roads, and Lusaka on the road map is defined simply as a crossroads from which spring the 'Great North Road', the 'Great East Road', the 'Kafue Road' heading southerly, and the 'Mumbwa Road' heading West. I've followed the Great North Road almost as far as it reaches, straight up into the Northern Province, and turned off to the NorthWest reaching the town of Kasama. From here the road deteriorates markedly and is badly potholed. The last 250 km takes one to a T-junction. 5 km to the right is the town of Mbala. 25 km to the left however is my destination. Following this, the road drops quite swiftly through a thousand metres as you drop into the Rift Valley. Surrounded by the heights of the Zambian plateau is Lake Tanganyika. My road lies parallel to the valley and the lake and meets the shores at a small dusty down called Mpulungu, generally pronounced 'poolungoo', and we're 1140 km North of Lusaka at Zambia's only port.