Many years ago I was a guest woodworking instructor at a craft school in Vermont. My accommodations for the week consisted of a small dormitory-style room with a bunk bed. The bed, made of rough-sawn timbers, was a simple, handmade one. The rails, head and footboards sat in deep and wide da-dos cut into the four bed posts and bolted in place. The structure was strong and stable and was the inspiration for the joinery I used in the sandbox.
Materials: I used off-the-shelf pressure-treated lumber to build this sandbox project but you can easily use any other wood suitable for the outdoors. You can also use regular lum-ber and apply a coat of paint or outdoor finish to protect it from the elements.
The sandbox consists of two sides and a front and back that are joined to the four posts, (towers) by deep and wide dados. The bottom of the box is a piece of 3/4” thick plywood that sits atop 3/4” square strips ( cleats ). Dentil molding, faux stained glass windows, and fence post caps are applied to give the sandbox its castle aesthetic.