Beautiful and unique cairns made of natural river rocks with Cairn 8-stone Zen Gardening. This popular art form, enjoyed by many around the world, involves carefully balancing rocks on top of each other. Each cairn is held together with metal pegs and predrilled holes, making it easy to assemble. Perfect for indoor or outdoor use, these cairns are 7.5" x 3" x 13" in size and no two are identical.