Its where the two Niles meet. It has been described as the world's largest waiting room. From personal experience this is not unfair.
Nothing happens in a hurry here. The word for 'urgency' does not exist. You just keep your patience, wait and wait. Otherwise it can drive you slowly mad. Even without doing very little of note, the city seems to exhaust you and wear you down.
I got pulled over yesterday in Omdurman market by a stern plain clothed man. It was a fairly innocuous area. But he told me he was from the Tourism Police. I was not to take photos, he insisted. He demanded to see my passport. After trying hard not to laugh at his title, I had no choice but to comply. He didn't seem in a mood to argue.
Sure, I said, no more photos. I walked on down the road. After waiting until he was well out of sight, I continued taking photos. This side of the Sudanese government is unpleasant and extremely counter productive to the enjoyment of being in a fascinating country.
It is also a total contrast to the wonderful nature and generosity of the vast majority of the Sudanese people. They are several worlds away from their government in so many senses of the world. Sanctions have punished them in the same way they have punished the ordinary and poor people of Burma.
I wish more people had the capacity or initiative to take their curiosity beyond the simplistic and often misleading news headlines, to climb over the easy and lazy negative assumptions we make and solidify about countries we know so very little about from the inside.
And yet, the notoriously slow and unhurried Khartoum appears to be changing. Or at least undergoing a dramatic visual facelift. The Chinese haven't just arrived. As quietly and discreetly as they always seem to do, they have built themselves upwards and concreted their way into influence and power here.
Colonel Gaddafi has erected an outrageously attention grabbing shiney tower. Maybe he knows a thing or two about what is going to happen in this big and mysterious country.