The great pyramid of Gaza built in 2584 B.C. by Egyptians are the only surviving of the Ancient 7 Wonders of the World. They were built mainly on the west bank of the Nile by King Khufu and took 20 years to build It took 2.5 million blocks of stone, weighing 2.25 tons each. It stands 481 feet high and covers 13.1 acres. They had no tools like pulleys to help them lift the massive blocks. Entrance was on the N. side and when the king was buried, they were sealed by a great steone. Unfortunately tomb robbers found ways to brfeak inside and rob it of its treasures. At one time there were 90 pyramids in ancient Egypt.