portion 36 in spaced relation from the viewable surface 34 with the rearwardly facing portion 36 including stop surfaces 38 40 as will be discussed later the stop surfaces 38 40 enable adjacent courses of blocks to be operatively connected to each other for purposes of this application the term operatively connect is understood mean that movement between adjacent courses of blocks in response to pressure exerted by retained material and water is resisted by complimentary confornting surfaces in adjacent courses of blocks referring again to fig2 and 3 each horizontal block includes a rear member 42 having opposing sides 44 b 46 b interior surfaces 48 a an exterior surface 48 b a top 50 and a bottom 60 rear member 42 is held in spaced relation from the front member 32 by a web 74 the web 74 includes opposing sides 76 78 an upper surface 80 and a lower surface 82 as with the viewable surface 34 the rear member 42 and opposing sides 44 b 46 b will not be discussed in detail with regard to fig2 the top 50 of the block includes top support surfaces 52 54 that are configured to operatively contact bottom support surfaces 62 64 of overlying courses of blocks see fig6 9 the top 50 of the block 30 also includes a recess 56 that extends downwardly from the upper surface 80 of the web 74 and downwardly relative to the top support surfaces 52 54 the recess 56 includes a stop surface 58 that is in alignment with the stop surfaces 38 40 of the rearwardly facing portion 36 of the block 30 together these stop surfaces 38 40 and 56 extend substantially along the entire width of the block.