It started off as a cupboard I got in second hand shop for £3 that was closing down. I then used sheets of polysterene stuck them to the sides with no more nails, left them stick and then built the platforms and caves with thicker poly and stuck them together with no more nails but held them in place with cocktail sticks. Then I used ready mixed grout with adhesive from B&Q thier own brand. and once that was dry I painted it with acrylic paint from the art dept from The Range store. then I used the fleck stone effect plasticote spray to spray over the paint and to finish off I coated it all in B & Q own brand outdoor varnish which is the same as yacht varnish only cheaper.