When you first get to Cairo, you will probably be in "I must see pyramids mode." And after Giza, the next logical set of pyramids to see is the State Pyramids at Sakurra. They are located about 40 minutes past the pyramids at Giza. Although much less famous, they are actually the first pyramids built in Egypt. The pyramids were built in the 3rd Dynasty (around 3000 B.C.) by King Zoser.
You will see three pyramids at Sakurra. There is a very large pyramid, a mostly collapsed one, and a medium-sized one. The burial tombs around the pyramid have some fantastic hieroglyphics, and you can spend a decent amount of time just wandering around. It is also interesting to learn about the false tombs and tunnels that were used to deceive grave robbers.
One other striking aspect of these pyramids is the desert view contrasted with the lush valley view. To get to the pyramids, you travel through a relatively lush strip along the Nile. But when you get to the pyramids, you cross this invisible line of lushness into rocky, barren desert. It was pretty shocking how big a difference a few hundred yards could make.
I recommend you see these pyramids so that you can contrast the different styles with the pyramids of Giza. Also, the crowds are much smaller, so you can really relax and move around in a very serene environment. But I chose not to venture out to even further pyramids. I guess you could say that I was "pyramid-ed out." As a nice pit stop on your way to Sakurra, make sure you stop by a carpet factory (see separate journal entry).