Apart from Cairo, which other capital city stands on the river Nile?

Khartoum is the capital and largest city of Sudan and the state of Khartoum. It is located at the confluence of the White Nile, flowing north from Lake Victoria, and the Blue Nile, flowing west from Ethiopia. The location where the two Niles meet is known as "al-Mogran". The main Nile continues to flow north towards Egypt and the Mediterranean Sea.

Divided by the two Rivers Nile, Khartoum is a tripartite metropolis with an estimated overall population of over five million people, consisting of Khartoum proper, and linked by bridges to Khartoum North and Omdurman to the west.

Sudan, in northeast Africa, measures about one quarter the size of the United States. Its neighbors are Chad and the Central African Republic to the west, Egypt and Libya to the north, Ethiopia and Eritrea to the east, and South Sudan, Kenya, Uganda, and Democratic Republic of the Congo to the south. The Red Sea washes about 500 mi of its eastern coast, and it is traversed from north to south by the Nile, all of whose great tributaries are partly or entirely within its borders.

Khartoum is located in the middle of the populated areas in Sudan, at almost the northeast center of the country between 16 degrees latitude north, 15 degrees latitude south, longitude 21 degrees west, and 24 degrees longitude east. It expands an area amounting to 20,736 km (12884 Mile) square between the West Bank of the River Nile.