Pyramids

Pyramids, large structures with four triangular sides that meet in a point at the top, directly over the center of the pyramid's square base. Ancient peoples in several parts of the world built pyramids, but the Egyptians constructed the biggest and most famous pyramids, with which this article deals. For information on the pyramids of Mesopotamia, see Ziggurat. For information on the pyramids of the Americas, see Pyramids (The Americas).

The ancient Egyptians built more than 90 royal pyramids, from about 2630 BC until about 1530 BC. During this time, the pyramid form evolved from a series of stepped terraces that resembled the layers of a wedding cake to most of the world, sloped pyramidal shape. The first pyramid, the Step Pyramid at Şaqqārah, was constructed during the reign of King Djoser (2630 BC-2611 BC).

Egyptian pyramids are the mysteries of the Eygpt for everyone has an idea what they were used for but no one can be really sure if it is true. The Pyramids mostly served as tombs for kings and queens, but they were also places of ongoing religious activity. After a ruler died, his or her body was carefully treated and wrapped to preserve it as a mummy. According to ancient Egyptian belief, the pyramid, where the mummy was placed, provided a place for the monarch to pass into the afterlife. In temples nearby, priests performed rituals to nourish the dead monarch's spirit, which was believed to stay with the body after death. In the Old Kingdom (a period of Egyptian history from about 2575 BC to about 2134 BC), Egyptian artists carved hieroglyphs on the walls of the burial chamber, designed to safeguard the dead monarch's passage into the afterlife. These hieroglyphic writings, which include hymns, magical spells, instructions on how to act in front of the gods, and other pieces of useful knowledge, are known as the Pyramid Texts.

During the Old Kingdom, the Egyptians built their largest and most ambitious pyramids, typically of large stone blocks. Over time, the size and quality of the pyramids decreased, probably because they were extremely costly. In the Middle Kingdom (2040 BC-1640 BC), the Egyptians built pyramids mostly of mud brick. All pyramids were aligned to the cardinal directions, meaning that their sides ran almost exactly due north-south and east-west. Most pyramids rose from desert plateaus on the west bank of the Nile River, behind which the sun set. The Egyptians believed that a dead monarch's spirit left the body and traveled through the sky with the sun each day. When the sun set in the west, the royal spirits settled into their pyramid tombs to renew themselves.

The internal layout of pyramids changed over time, but the entrance was typically in the center of the north face. From here a passage ran downward, sometimes leveling out, to the king's burial chamber, which ideally was located directly underneath the pyramid's center point. Sometimes, in addition to the burial chamber, there were storage chambers within the pyramid. These chambers held objects used in burial rituals as well as items for the deceased to use in the afterlife. Some of these items were valuable, and in later years people robbed many of the pyramids and stole the objects.

A pyramid never stood alone in the desert. Instead, it was the focus of a complex of temples and smaller pyramids. Priests and officials entered a typical pyramid complex through a temple near a harbor connected to the Nile by a system of canals. This so-called valley temple was linked to the pyramid by a long, covered walkway, known as a causeway. The causeway ran up from the valley through the desert to another temple, called a pyramid temple or mortuary temple. This temple was connected to the pyramid at the center of its eastern face.

Most pyramid complexes had satellite pyramids and queens' pyramids. The satellite pyramids were too small to serve as burial places, and their purpose remains mysterious. They may have contained statues representing the king's ka, an aspect of his spirit. The queens' pyramids were simpler, smaller versions of the kings', sometimes with small temples all their own. They were intended for the burial of a king's principal wives.

The Egyptian pyramids developed from royal tombs of the earliest periods of Egyptian history. In the 1st and 2nd dynasties (2920 BC-2770 BC and 2770 BC-2649 BC), kings were buried at the city of Abydos in graves topped with a pile of clean sand inside low-lying brick walls. By the 3rd Dynasty (2649 BC-2575 BC), kings were being buried underneath large mud brick rectangles called mastabas, from the Arabic word meaning "bench."

King Djoser, who reigned from 2630 BC to 2611 BC, built a more elaborate royal tomb known as the Step Pyramid at Şaqqārah. This tomb started out as a mastaba, but its architect, Imhotep, first expanded the mastaba then topped it with successively smaller mastabas. In the end, Djoser's tomb looked like a rectangular wedding cake with six layers.

The Step Pyramid and later pyramids of the 3rd Dynasty were constructed of small, almost brick-sized stones that were laid in vertical courses and inward-leaning to create the sloped sides.

King Sneferu, the father of Khufu, built the initial true pyramids, developing the new technique during construction. The earliest true pyramid, was built at the town of Maydūm, began as a step pyramid with inward-leaning walls and eight levels. After working on the structure for 14 years, Sneferu moved his burial ground north to Dashur for unknown reasons, and construction began on another pyramid. This one, too, was made of stone blocks that leaned inward. The architects had designed it with an angle of 60 degrees (to the ground), but as the pyramid rose, it started to sink because of the weight and angle of the stones. To solve this problem, the builders put up an outer supporting wall, giving the half-finished pyramid a shallower angle of 55 degrees. After this, the architects finished the upper portion of the pyramid off with a slope of only 43 degrees. This shift in angle from 55 to 43 degrees gives this pyramid its name--the Bent Pyramid.

During construction of the Bent Pyramid, the architects made a discovery: On the upper portion, instead of leaning the stones inward, they laid down horizontal layers of larger stone blocks. With the new technique, the pyramid shape resulted because each level was slightly smaller than the one it lay upon. The new technique was then used to construct another giant pyramid for Sneferu, now called the North Pyramid, located about 1.6 km (1 mi) north of the Bent Pyramid. It proved so successful that Sneferu returned to Maydūm, while construction was still in progress on the two Dashur pyramids, and refined the Maydūm pyramid by adding an outer