The Samarra Barrage is a large dam and diversion structure on the Tigris River, completed in 1954, that controls water flow into the Tharthar Depression to the west — Iraq's largest lake. The barrage serves flood control and irrigation functions across a large swath of central Iraq and is an impressive piece of engineering.
From the road that crosses the barrage, you get a good view of the Tigris itself — a broad, brown, slow-moving river here, its banks lined with date palms. The Tharthar depression, which was formed by flooding agricultural land to create the reservoir, stretches far into the western desert. The barrage is not a formal tourist site but is easy to see from the road when driving between Samarra and Baghdad.