#21 Cairo, Egypt
29°58′34″N 31°7′58″E. The Great Pyramids of Giza are located on the outskirts of Cairo, Egypt. Dating back to 2580 BC, the Great Pyramid, the largest structure at the site, is the oldest of the Seven Wonders of the Ancient world and the only one to remain largely intact. With an estimated 2,300,000 stone blocks weighing from 2 to 30 tons each, the 481 foot pyramid was the tallest structure in the world for more than 3,800 years.
