<human>:  How many blocks of stone were used to build the Great Pyramid of Giza?
<bot>: The Great Pyramid of Giza is made up of over 2.3 million stone blocks. The largest of these blocks are called "casing stones," which are used to support the weight of the pyramid. The casing stones are made of limestone, and each weighs about 150 tons. The Great Pyramid is the only one of the Seven Wonders of the Ancient World that still stands.