Since this is my favorite thread on this board and I haven't really put in my 2 cents, I thought I might add a few interesting facts about the Great Pyramid.
The sides of the pyramid are lined up almost exactly with the cardinal points of the compass. The accuracy of this alignment is extraordinary, with an average discrepancy of only about three minutes of arc in any direction or a variation of less than 0.06 percent.
The Great Pyramid functioned as an enormous sundial. Its shadow to the north, and its reflected sunlight to the south, accurately marked the annual dates of both the solstices and the equinoxes.
The basic dimensions of the Great Pyramid incorporate measurements from which the earth's size and shape can be calculated. The pyramid is a scale model of the hemisphere, incorporating the geographical degrees of latitude and longitude. The latitude and longitude lines that intersect at the Great Pyramid (30 degrees north and 31 degrees east) cross more of the earth's land surface than any other lines, thus the pyramid is located at the center of the land mass of the earth (the pyramid is built on the closest suitable site to this intersection). The original perimeter of the pyramid equals exactly one-half minute of latitude at the equator, indicating that its builders measured the earth with extreme precision and recorded this information in the dimensions of the structure. Altogether these measurements show that the builders knew the exact dimensions of the planet as precisely as they have been recently determined by satellite surveys.
The foundation of the Great Pyramid is amazingly level., No corner of its base is more than one-half inch higher or lower than the others. Considering that the pyramid's base covers more than thirteen acres, this near-perfect leveling far exceeds even the finest architectural standards of the present day.
Measurements throughout the pyramid show that its constructors knew of the proportions of pi (3.14...), phi or the Golden Mean (1.618), and the "Pythagorean" triangles thousands of years before Pythagoras, the so-called father of geometry, lived.
Measurements show that the builders knew the precise spherical shape and size of the earth and had accurately charted such complex astronomical events as the precession of the equinoxes and the lunar standstill dates. The minute discrepancies of the lengths of the base of the pyramid (several inches over the 230 meter length of its base) reveal not an error on the part of the builders but an ingenious means of incorporating into the pyramid the "discrepancies" of the earth itself, in this case the flattening of the earth's globe at the poles.
Shafts leading upward from the two main chambers, previously thought to be air shafts for ventilation, have been shown to have another possible purpose. A miniature electronic robot mechanically crawled sixty-five meters up the shafts and its findings suggested that the south and north shafts in the Kings Chamber are pointed to Al Nitak (Zeta Orionis) and Alpha Draconis respectively, while the south and north shafts of the Queens Chamber point to Sirius and Orion. The scientists conducting this research believe that the layout of the three pyramids on the Giza plateau precisely mirror the position of the three main stars in the Orion constellation. (While crawling along one of the shafts in the Queens chamber, the robot's cameras photographed a previously unknown closed door that may lead to some hidden chamber.) Readers interested in these new findings should consult The Orion Mystery by Robert Bauval and Adrian Gilbert.
http://www.sacredsites.com/africa/egypt/great_pyramid.html