Giza's great pyramids is an incredible sight, thirty times larger than the Empire state building (in Mass), the pyramids features are so extensive they can be seen from the moon. The oldest structure in existence, having been started 4,617 years ago, is the sole remnant of the world's seven wonders.
The great pyramids did not always look 'rough' as it does today.
Originally it was encased with a layer of tight-fitting, highly polished 20-ton stone slabs. W. M. Flinders Petrie determined the exact dimensions of the sides of the pyramids, and he found that they were almost the same length to an accuracy of 0.1 +/- inch.
The great pyramids are the most comprehensively studied building in the world. It sited at the northern edge of the Giza plateau.