After reading the section on Egyptian pyramids yesterday in Story of the World and then reading a bit more about them in Pyramids and Mummies (great easy reader on the subject!), we dumped out the Legos and built two small pyramids according to the instructions in the Story of the World activity book. The block options are to make your own blocks out of sand or use sugar cubes or Legos. Although I'm sure making the sand blocks would have produced a more realistic looking facsimile, I'm all about projects that are easily dismantled because my kids are pack rats. If we had built a pyramid out of sand cubes, it would still be in my house when they were 20 and off at college. :-)
Then, in the end, we built the behemoth "Great Pyramid" in the photo above. Currently, Red has erected it on top of her headboard in her room.