The Great Pyramid of Giza is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact. Egyptologists believe that the pyramid was built as a tomb over a 10- to 20-year period concluding around 2560 BC. Initially standing at 146.5 metres (481 feet), the Great Pyramid was the tallest man-made structure in the world for more than 3,800 years until Lincoln Cathedral was finished in 1311 AD.