Atbarah (sometimes Atbara) (Arabic: عطبرة‎) is a town of 111,399 (2007) located in River Nile State in northeastern Sudan. It is located at the junction of the Nile and Atbarah rivers. It is an important railway junction and railroad manufacturing centre, and most employment in Atbarah is related to the rail lines. It is known as the "Railway City' and The National Railway Company's headquarters are actually located here in Atbarah.

The confluence of the Nile and its most northern tributary, the Atbarah (Bahr-el-Aswad, or Black River) was a strategic location for military operations. In the Battle of Atbara, fought on 8 April 1898 near Nakheila, on the north bank of the river, Lord Kitchener's Anglo-Egyptian army defeated the Mahdist forces, commanded by Amir Mahmud Ahmad. Kitchener's strengthened position led to a decisive victory at the Battle of Omdurman on 2 September 1898, giving the British control over the Sudan.

The first trade union in Sudan formed in 1946 among railroad workers in Atbarah. The city also is home to one of Sudan's largest cement factories (Atbara Cement Corporation). The town was the centre of the Sudanese railway industry. Few trains are made here now and rail traffic is much reduced. The original station and unusual dome-shaped houses of railway workers remain.

In geology, a rift or chasm is a place where the Earth's crust and lithosphere are being pulled apart and is an example of extensional tectonics.

Typical rift features are a central linear downfaulted segment, called a graben, with parallel normal faulting and rift-flank uplifts on either side forming a rift valley, where the rift remains above sea level. The axis of the rift area commonly contains volcanic rocks, and active volcanism is a part of many, but not all active rift systems.

Major rifts occur along the central axis of mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates.

Failed rifts are where continental rifting began, but then failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to the point of seafloor spreading, while the third ultimately fails, becoming an aulacogen.