The Great Pyramid of Giza
Completed around 2560 B.C., Egypt's Great Pyramid is also the only one of the seven ancient wonders that exist today. When it was finished, the pyramid had a smooth exterior and reached a height of 481 feet. Archaeologists say it took as long as 20 years to build the Great Pyramid, which is thought to have been built to honor the Pharoah Khufu.