This is the Cheops pyramid. All the pyramids were built out of limestone which could only be found in Aswan which is hundreds of kilometres away. It is still a mystery how they managed to bring the stones up here. I'm not sure but I think the guide told us that it took about 65 years to build a pyramid. 1'000'000 people worked here (hm, I think it was per year but I'm not sure;-)