The Great Pyramid was built around 2560 BC. It is also known as the Pyramid of Khufu and the Pyramid of Cheops. Even though it is the oldest of the Great Pyramids, it is also the largest. Its purpose was to be a tomb for the fourth dynasty King Khufu, and also to connect him with the gods. It took about twenty years to build and remains the most massive thing ever built.

Next to the pyramid were four smaller pyramids. These may have been either for Khufu’s wives, or possibly one for each of the Canopic jars containing the king’s organs which would have been removed during mummification. One pyramid is ruined, so only three are visible today. The flat structures near the pyramid are flat-roofed tombs (called mastabas) for the nobles, as it was then the custom for high ranking people to be buried close to their ruler.

The pyramid has 3 main chambers. The lowest chamber is dug out of the rock below the pyramid. The two higher chambers, known as the Queen’s Chamber and King’s Chamber, are in the pyramid. It may well have been that each of the lower chambers was a kind of insurance chamber in case the king died before the pyramid was finished.

It is not known exactly how long it took to build, but probably between 14 and 20 years. When finished it would have been 146m tall, which is exactly 280 Egyptian cubits (the measure they used at the time). The 2.3 million stones in the pyramid weigh nearly 6 million tonnes. This means that to build the pyramid over 20 years, a massive 800 tonnes of stone would have to have been hacked out of the nearby quarry, pulled to the pyramid, taken up ramps, shaped to fit to within a millimetre or two, and fitted into place each day.

It is an amazingly accurate construction. Over the whole base there is only 21mm out of level and each side varies from the others in length by no more than 58mm. The sides of the base each line up with the main points of the compass. The four outer faces slope at 51.843° and the length of each base is 233m.

In addition to the main blocks of limestone used to make the pyramid, the casing slabs came from a quarry on the other side of the Nile. The faces of the king’s chamber are also made of massive granite slabs, which weigh between 25 and 80 tonnes. These were quarried 800km upriver at Aswan and floated down the Nile.

The casing stones were shaken loose of the core by an earthquake around 1300AD and many fell off the core and on to the surrounding desert. This allowed people to carry off the stones for use as mosques and forts in nearby Cairo.

Although many slaves may have been involved in pushing the stones over rollers, the final placing and cutting was done by an army of skilled paid workers. They lived in makeshift villages nearby. To them, working on this great project was a great honour.

When they built the pyramid, the architects knew that they would be burying fabulous treasures along with the body of their king, and so they built in many measures to try to defeat any later grave robbers. This included massive slabs of rock that fell down into the passage to the burial chamber, blocking it. Unfortunately they were not successful at preventing almost complete looting.

The tombs were known to have been looted by Ancient Egyptians in Middle Kingdom times, and the entrance used by tourists today is the one made by robbers in the 9th century AD – who, of course, found the tomb empty. The King’s Chamber is 11m from east to west and 6m north to south. It has a flat roof 6m above the floor. One metre above the floor there is an “air shaft” in the north and south walls which appears to be aligned on stars, and this is one reason people think that the pyramids were intended to be a link between heaven (the stars) and Earth.

The King’s Chamber is faced with granite blocks that fit together so closely that even a sheet of paper cannot be pushed between them. The sarcophagus (stone coffin) inside is larger than the passageways leading to it, so it must have been put in place during the construction of the pyramid.

Around the pyramid are shallow pits that held royal boats intended to help the pharaoh sail away to the heavens. One of these boats has been re-assembled and the cedar-wood boat, nearly 50m long, is the centrepiece of a small ‘solar boat’ museum next to the pyramid.