The Great Pyramid of Giza, also called Khufu's Pyramid or the Pyramid of Khufu, and Pyramid of Cheops, is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now Cairo , Egypt, and is the only remaining member of the Seven Wonders of the Ancient World. It is believed the pyramid was built as a tomb for Fourth dynasty Egyptian King Khufu (Cheops in Greek) and constructed over a 20 year period concluding around 2560 BC. The Great Pyramid was the tallest man-made structure in the world for over 3,800 years. Originally the Great Pyramid was covered by casing stones that formed a smooth outer surface, and what is seen today is the underlying core structure. Some of the casing stones that once covered the structure can still be seen around the base. There have been varying scientific and alternative theories regarding the Great Pyramid's construction techniques. Most accepted construction theories are based on the idea that it was built by moving huge stones from a quarry and dragging and lifting them into place.
There are three known chambers inside the Great Pyramid. The lowest chamber is cut into the bedrock upon which the pyramid was built and was unfinished. The so-called Queen's Chamber and King's Chamber are higher up within the pyramid structure.
The Great Pyramid of Giza is the main part of a complex setting of buildings that included two mortuary temples in honor of Khufu (one close to the pyramid and one near the Nile), three smaller pyramids for Khufu's wives, an even smaller "satellite" pyramid, a raised causeway connecting the two temples, and small mastaba tombs surrounding the pyramid for nobles. One of the small pyramids contains the tomb of queen Hetepheres (discovered in 1925), sister and wife of Sneferu and the mother of Khufu. There was a town for the workers of Giza, which included a cemetery, bakeries, a beer factory and a copper smelting complex. A few hundred meters south-west of the Great Pyramid lies the slightly smaller Pyramid of Khafre, one of Khufu's successors who is also commonly considered the builder of the Great Sphinx, and a few hundred meters further south-west is the Pyramid of Menkaure, Khafre's successor, which is about half as tall. In May 1954, 41 blocking stones were uncovered close to the south side of the Great Pyramid. They covered a 30.8 meter long rock-cut pit that contained the remains of a 43 meter long ship of cedar wood. In antiquity, it had been dismantled into 650 parts comprising 1224 pieces. This funeral boat of Khufu has been reconstructed and is now housed in a museum on the site of its discovery. A second boat pit was later discovered nearby.
Although succeeding pyramids were smaller, pyramid building continued until the end of the Middle Kingdom. However, as authors Briar and Hobbs claim, "all the pyramids were robbed" by the New Kingdom, when the construction of royal tombs in a desert valley, now known as the Valley of the Kings, began. Joyce Tyldesley states that the Great Pyramid itself "is known to have been opened and emptied by the Middle Kingdom", before the Arab caliph Abdullah Al Ma'mun entered the pyramid around 820 A.D.