Rocks made from stuffed brown paper lunch bags, glued shut, spray painted with several stone colors, and textured stone spray paint here and there too...good for many kinds of biblical lessons along the journey.
DIY Stalagmites VBS Cave Quest. Dollar Tree Noodles & Flower Wire. Plus Great Stuff Foam. Use flower wire to thread & wrap pool noodles that you have cut to various sizes. Don't worry it will dry & won't stick to plastic.