We timed it perfectly to learn about rocks in science and Stonehenge in Mystery of History. You can find our ROCK lesson here . Its hard to imagine standing up 28 ton slabs of rock and making a perfect circle. The girls went rock collecting and tried to guess what type of rock their rocks may have been and then tried to stack up their own rocks to make a perfect circle like Stonehenge. Then we pulled out the dominoes and made our own version of Stonehenge, although dominoes aren't that easy either with falling and making a perfect circle...so imagine having 28 tons of a rock slab that's not a perfect rectangle. :)