A block for use in constructing a multiple course retaining wall. The block has a substantially planar top surface, a front surface, wherein said front surface is of a substantially curvilinear shape, a rear surface, opposed side surfaces, and a bottom surface. The bottom surface has a predetermined area and a non-planar portion, with the non-planar portion comprising a continuous area making up at least one-quarter of the bottom surface and creating a cavity between the bottom surface of the block and a top surface of a lower course of blocks when the block is placed on the top surface of the lower course of blocks. The cavity allows dirt and other foreign matter to exist between successive courses of blocks without creating instability between the block and the lower course of blocks.