You can make SIDEWALK by combining RED BRICKS and GREY BLOCK. SIDEWALK belongs to farm category. SIDEWALK is good to plant before you head to some parkours. You get experiance points for breaking SIDEWALK. SIDEWALK can be broken. By default you should get at least 1 seed back. Profiting with this might be questionable. Will you get enough blocks to build something? You just have to find out yourself.