I used stackable"garden bricks which are each 6 inches in height. So this bed is one foot in height, I chose to use an 8x4x4 and a 4x4x4 for the length to give a staggering effect with the bricks hopefully to give more support.

The brick have a small hole in the center, so if I wanted to give the bed more height I can but I think the bed would have to be stabilized with some rebar that would easily fit through the hole.

The wood is untreated and eventually will rot but then I will simply replace the wood. The whole process was very simple and way easier than using wood screws and posts to make the bed.