Of the Seven Wonders of the Ancient World, Khufu's Pyramid (or the Pyramid of Cheops) is the only survivor. The Great Pyramid is located just outside Cairo, Egypt, and it is the best known structure in the world. When it was built, the Great Pyramid was 145.75 meters high, but over the years. It has lost part of its top. It covered an area of 53,000 square meters. That is large enough to hold the cathedrals of Florence, Milan, St. Peter's. Westminster Abbey, and St. Paul's combined. The Great Pyramid remained the tallest structure on Earth for more than 43 centuries. It is still an impressive 138.7 meters today, and it must have been even more impressive to visitors in the past, when there was no taller structure in the entire world.