Mastaba tombs of high officials at Giza, seen from the top of the Great Pyramid.

Why are archaeological expeditions important? How do they get started, how are they run, and how long do they last? What happens to what the expedition finds? The answers to these questions change from country to country, generation to generation, and even year to year.

Usually an archaeological expedition gets under way because forces of nature, modern development, or even treasure hunters threaten an ancient site. Often an archaeologist knows from surveys that a site is worth exploring. He or she hopes that excavating the site will help answer questions or test theories about an ancient culture. But the country of the site must grant a permit. In the case of the Museum Expedition at the pyramids of Giza, the Egyptian antiquities authorities asked several foreign expeditions to excavate the site in order to stop the damage being done by plunderers.

Detail of the mastaba tomb of Babaef at Giza, excavated by the Museum Expedition.