When we learned about ancient Egypt, I put a pyramid in the dramatic play area. I made it several years ago (with the help of my brothers!) and it's still in great shape. We used a refrigerator box. Three sides of the pyramid are all one piece and for the last side, I taped on a half-sized triangle. That way I could see what was going on in there at all times!
I had little lanterns in there and some books about ancient Egypt. Two kids at a time could go in the pyramid to read the books. Later in the week I put paper on the inside walls and the kids drew on them, just like the Egyptians did.