Dam across the Nile River , north of Aswan , Egypt.
Built 4 mi (6 km) upstream from the earlier Aswan Dam (1902), it is 364 ft (111 m) high and 12,562 ft (3,830 m) long. Differences with Gamal Abdel Nasser led the U.S. and Britain to withdraw their financial support of the project in 1956, whereupon Nasser turned to the Soviet Union for assistance. The dam, completed in 1970, impounds the reservoir Lake Nasser and controls the annual Nile flood, releasing floodwaters when needed for irrigation; it also enables the production of great amounts of electric power. Its construction necessitated the relocation of the ancient Abu Simbel ruins.