Great Pyramid of Giza
The Great Pyramid of Giza
It is the one and only Wonder which does not require a description by early historians and poets. It is the one and only Wonder that does not need speculations concerning its appearance, size, and shape. It is the oldest, yet it is the only surviving of the Seven Ancient Wonders. It is the Great Pyramid of Giza. The area covered by the Great pyramid can accommodate St Peter's in Rome, the cathedrals of Florence and Milan, and Westminster and St Paul's in London combined.
When it was built, the Great pyramid was 145.75 m (481 ft) high. 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 was covered with a casing of stones to smooth its surface (some of the casing can still be seen near the top of Khafre'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%.
How Tall?
At 146.5 m (481 ft) high, the Great Pyramid stood as the tallest structure in the world for more than 4,000 years. Today it stands at 137 m (449.5 ft) high, having lost 9.5 m (31 ft) from the top.
Here's how the Great Pyramid compares to some modern structures.
BlocksHow Heavy?
More than 2,300,000 limestone and granite blocks were pushed, pulled, and dragged into place on the Great Pyramid. The average weight of a block is about 2.3 metric tons (2.5 tons).

How Wide?
The base of the Great Pyramid is a square with each side measuring 230 m (756 ft) and covering an area of 5.3 hectares (13 acres).
How much is that? Imagine a football field. Nearly 10 football fields could fit within the base. The area of the base is also equal to about seven city blocks in New York City.

How Steep?
Each side of the Great Pyramid rises at an angle of 51.5 degrees to the top. Not only that, each of the sides are aligned almost exactly with true north, south, east, and west. More than eighty (80) pyramids were built around the Nile from 1600 - 2700 BC. There were 3 different types of pyramids: The Step Pyramid, the Bent Pyramid, and the Straight Sided Pyramid.

The Step Pyramid - A pyramid made of large clear steps.
The Bent Pyramid - A straight sided pyramid, until near the top where it bends inward at a sharper angle.
The Straight Sided Pyramid - The normal pyramid that we see usually see in movies and books. All 4 sides of it bend in to the top-center. The Pyramids still hold many a mystery as to how humans could transport and lift heavy stone blocks with only basic tools. Some people say this task could not be done even with today's technology, and others believe that "alien beings" were responsible for the construction of the pyramids.

Another mystery of the pyramids is the fact that they are exactly in line with certain stars. Most pictures of the pyramids show tham as having a rough surface with 'steps' leading all the way up. When they were first built it is known that the pyramids were covered in quartz and were very smooth and glossy which is quite hard to imagine. Over time people took the quartz, partly to make new buildings and partly to make the pyramids easier to climb. For a pyramid to look like a pyramid, each of the four triangular-shaped sides must slope up and towards each other at the same angle so that they meet at a point at the top. The builders constructed the pyramid layer by layer, starting at the bottom. They had to check their work often, for even a tiny error at the bottom could grow into a very large error by the time the workers reached the top! It has been suggested that there are enough blocks in the three pyramids above to build a 3 m (10 ft) high, 0.3 m (1 ft) thick wall around France.
Wall at Karnak