Once you've made a sand castle, expand the pretend play by carving a river from the castle to the sea. Add rocks for boulders, dig waterfalls, and build tiny boats the kids can sail to open waters.

Ease it down the edges, smoothing it as you go, then trim the base to make it flush to the sandcastle. Top the corners with four squares of yellow fondant. 8. Roll out some brown fondant and cut ...