It was the first time Prince Charles has been in Cairo for 15 years. Princess Diana posed for photos at the site in 1992.The Great Pyramids of Giza were built 4,500 years ago and are among the Seven Wonders of the Ancient World. The towering 146 metre (481ft) high Great Pyramid of Giza, also called Khufu, remained the tallest building in the world for 4,000 years. It is made of two million bricks each weighing 50 tonnes.