A stackable concrete wall block is disclosed having a body with an irregular front portion and a prism shaped rear portion, the irregular front portion has a three dimensional surface structure embossed in the front face providing the appearance of natural stone and the regular rear portion facilitating stacking of like blocks. The rear portion has parallel sidewalls perpendicular to a rear wall, which are more easily manufactured by dry casting than tapered sidewalls. A lip protrudes from at least one of the sidewalls of the rear portion and is coplanar with the front face for spacing the body of the block from that of a like block placed adjacent thereto. The lateral lip generates spacing between adjacent blocks at a back terminal edge, thereby allowing the assembly of curved walls. The irregular front face extends over the lip so that the front face is continuous over the lip.