Volcano
Red candle wax; sand and 500ml water. Heat it.
Resources
500 ml or 600ml glass beaker with a 1 cm layer of red candle wax (previously melted and poured into the beaker), clean (washed) sand sufficient for a 1 cm layer, about 400 ml of very cold water, eye protection, safety screens, Bunsen burner, bench mat, tripod, gauze