Pyramids
The true pyramid exists only in Egypt. Usually of stone, it
is square in plan, with triangular sides facing the compass
points, sloping at an angle of about 50° and meeting at an apex.
The oldest Egyptian tombs are MASTABAS. The true pyramid evolved
about the IV dynasty (2680-2565 B.C.) and was favored through the
VI dynasty (2420-2258 B.C.). Later pyramid tombs were archaisms.
Each monarch built his own pyramid, in which his mummified body
might be preserved for eternity. Entrance was through an opening
in the north wall. A small passage, traversing lesser chambers,
led to the sepulchral chamber, excavated from the bedrock deep
beneath the immense pile. Usually of stone blocks laid in
horizontal courses, pyramids were sometimes of mud brick with
stone casing. Most notable are the three pyramids of Giza (IV
dynasty). The Great Pyramid of Khufu or Cheops (2680 B.C.), one
of the SEVEN WONDERS OF THE WORLD, is the largest ever built-13
acres (5.3 hectares) in area and 482 ft (147 m) high. Pyramidal
structures are found also in Mesopotamia (the ZIGGURAT) and in
Central America and Mexico. The Mayan pyramids, built in steep,
receding blocks, were topped by ritual chambers. Some had
interior tomb crypts.