'Esna Barrage acros the Nile', Egypt, early 1920s.
© Science Museum / Science & Society Picture Library
'View from the West Bank, showing the south (upstream) face and the lock entrance. Note - every tenth pier of double thicknes'. The Esna Barrage is south of Luxor in Egypt on the River Nile. It was built in 1906-1908 to control the waters of the annual Nile floods with the aim of improving irrigation and increasing the area of cultivable land.