From The Big Picture
The Colossi depict the Pharaoh Amenhotep III (14th century BC) and originally guarded the entrance to his massive mortuary temple complex. The name The Colossi of Memnon is probably of Roman origin. Memnon was the King of Ethiopia and a hero of the Trojan War. He was known as Ruler of the Dawn, and in ancient times the Eastern Colossus reputedly sang in the early morning heat. The Voice of Memnon was probably caused by evaporating water escaping from cracks in the rocks and was last heard in the second century AD.