Got these on clearance at wall mart. They are called project blocks by a company called florafoam. they are supposed to be for buildings,and I guess they would make great retaining walls too, But they are perfect scale hay bales for 1/32 tracks.
they come in a beige color,but they paint up well in a hay color. Great for Oval tracks , and vintage road courses. They come 300 to a box, so there are plenty!

