We've been reading bits of Castle by David Macaulay aloud together. It is a very detailed account about how a castle and the adjoining town were planned out and built. One section talked about how the castle walls were built. We tried to design our own walls to be as strong as possible. The drawing from Castle shows how thick the castle walls were constructed. We tried to do the same... The first time round, the rice made our wall buckle (and break). We learned the importance of mortar in binding the rocks together!! LD and DD designed this wall. And we reworked this wall with double rows of bricks and rice in the middle. Both castle wall designs were destroyed equally as easily by our spoon catapults, but the kids really listened, looked and learned a lot about how castle walls were built. Not to mention that they had a blast destroying the walls!! I could add in another 10 pictures of the new walls that were constructed and destroyed, but will leave it with this!!