The ancient egyptians built dams along the Nile. The egyptians built a dam that was 350 feet long, 40 feet high and 78 feet thick at the base. The dam was built in 2500 b.c. to supply a stone quarry just south of Cairo with water. Today, the mighty Aswan high dam is a symbol of modern day Egypt. 5 kilometers long at its crest, and 1 kilometer thick at its base, and rises 107 meters above sea level, its no wonder why it stands for so much.