The Great Pyramid of Khufu (circa 2600 BC) was the greatest of the Egyptian pyramids, which served as burial places of the pharaohs, particularly during the Old Kingdom. Some lists included all of the pyramids and the Sphinx as well.

     The great pyramids of Giza were built around 2700-2500 BC as tombs for the pharoahs (rulers of ancient Egypt, who held the status of gods on earth). The Great Pyramid of Khufu (Cheops to the Greeks) is the largest,pictured here in the center of the photograph, it covers 13 acres. It was constructed of around 2.3 million stones and each of the stones weigh from 2 to 30 tons each.

     Except for parts of the Mausoleum and of the temple of Artemis, they are the only one of the seven ancient wonders still standing. Of the seven wonders of the ancientworld, only the pyramids of Egypt have survived in a form that resembles their originalcondition. The largest of the three, known as the Great Pyramid of Khufu, was made up of approximately 2.3 million blocks of stone each weighing an average of 2.5 tons.Located in Giza on the west bank of the Nile River, near Cairo, the pyramids remainone of the engineering marvels of all time.

The granite slab that is the roof of Khufu's burial chamber weighs 50 tons in itself. Khufu's pyramid stands about 450 feet (137 meters) high. It is also in almost complete form, despite being the World’s oldest Wonder. The pyramid of King Chephren is behind Khufu's and the pyramid of King Mycerinus is in front. The three smaller pyramids in the front were built for King Mycerinus’ three wives.

     These monumental pyramids are precisely oriented to the four cardinal points. Today the city of Cairo reaches almost to the foot of the pyramids, but when the pyramids were built, they were in the middle of the desert. The Great Pyramids of Giza still have a strong impact on humanity. The impact is best summed up in this ancient Arab proverb: "Man fears Time, yet Time fears the pyramid."

History
      Of the three Great Egyptian pyramids, only the Great Pyramid of Khufu (Cheops) tops of the list of Wonders. It was built by the Egyptian pharaoh Khufu of the Fourth Dynasty around the year 2560 BC to serve as a tomb after his death. The tradition of pyramid building started in Ancient Egypt as a sophistication of the idea of a mastaba or "platform" covering the royal tomb. Later, several stacked mastabas were used. Early pyramids, such as the Step Pyramid of King Zoser (Djoser) at Saqqara by the famous Egyptian architect, Imhotep, illustrate this connection.

     The great pyramid is believed to have been built over a period 20 year. The site was first prepared, and blocks of stone were transported and placed. An outer casing (which disappeared over the years) was then used to smooth the surface. Although it is not known how the blocks were put in place, several theories have been proposed. One theory involves the construction of a straight or spiral ramp that was raised as the construction proceeded. This ramp, coated with mud and water, eased the displacement of the blocks which were pushed (or pulled) into place. A second theory suggests that the blocks were placed using long levers with a short angled foot.

     Throughout their history, the pyramids of Giza have stimulated human imagination. They were referred to as "The Granaries of Joseph" and "The Mountains of Pharaoh". When Napoleon invaded Egypt in 1798, his pride was expressed through his famous quote: "Soldats! Du haut de ces Pyramides, 40 siècles nous contemplent". (meaning: Soldiers! From the top of these Pyramids, 40 centuries are looking at us)

     As on date, the Great Pyramid is enclosed in the tourist region of the Giza Plateau, along with the other pyramids and the Sphinx. Also in the area is the museum housing the mysterious Sun Boat, only discovered in 1954 near the south side of the pyramid. The boat is believed to have been used to carry the body of Khufu in his last journey on earth before being buried inside the pyramid. It may also serve him as a means of transportation in his afterlife journey according to Ancient Egyptian beliefs.

The Structure
      The Great Pyramid was 145.75 m (481 ft) high when it was built. Over the years, it lost 10 m (30 ft) off its top. It ranked as the tallest structure on Earth for more than 43 centuries, only to be surpassed in height in the nineteenth century AD. It is made composed of 2,300,000 blocks of stone, each averaging 2 1/2 tons in weight. Despite the makers' limited surveying tools no side is more than 8 inches different in length than another, and the whole structure is perfectly oriented to the points of the compass.

     Until the 19th century it was the tallest building in the world and, at the age of 4,500 years, it is the only one of the famous "Seven Wonders of the Ancient World" that still stands. It is the Great Pyramid of Khufu, at Giza, Egypt. It was covered with a casing of stones to smooth its surface (some of the casing can still be seen near the top of Khefre's pyramid). The sloping angle of its sides is 51 degrees and 51 minutes.

     Each side is carefully oriented with one of the cardinal points of the compass, that is, north, south, east, and west. The horizontal cross section of the pyramid is square at any level, with each side measuring 229 m (751 ft) in length. The maximum error between side lengths is astonishingly less than 0.1%. On the north face, is the pyramid's entrance. A number of corridors, galleries, and escape shafts either lead to the King's burial chamber, or were intended to serve other functions.

     The King's chamber is located at the heart of the pyramid, only accessible through the Great Gallery and an ascending corridor. The King's sarcophagus is made of red granite, as are the interior walls of the King's Chamber. Most impressive is the sharp-edged stone over the doorway which is over 3 m (10 ft) long, 2.4 m (8 feet) high and 1.3 m (4 ft) thick. All of the interior stones fit so well, a card won't fit between them. The sarcophagus is oriented in accordance with the compass directions, and is only about 1 cm smaller in dimensions than the chamber entrance. It might have been introduced as the structure was progressing.