Egyptians used a form of lime and gypsum mortar as a binding agent. However that mix is not hydraulic. The Greeks continued with limestone but the first to discover hydraulic concrete are the Romans ( hydraulic means can't be melted with water) . read more
The Sphinx is made out of hard and soft limestone. Over the years, Ancient Egyptians added more and more stone to the forepaws of the Sphinx, therefore it is also made out of stone, too. read more
The Great Sphinx of Giza is an immense stone sculpture of a creature with the body of a lion and the head of a human. The greatest monumental sculpture in the ancient world, it is carved out of a single ridge of limestone 240 feet (73 meters) long and 66 feet (20 meters) high. read more