I claim the ornamental design for a retaining wall block, as shown and described.
FIG. 1 is a perspective view of a retaining wall block;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a front side elevational view thereof;
FIG. 5 is a rear side elevational view thereof;
FIG. 6 is a right side elevational view thereof; and,
FIG. 7 is a left side elevational view thereof.
The broken lines shown in the drawings are included for purposes of illustrating environment and form no part of the claimed design. The surface shading lines show contour and/or distinguish between open and solid areas. The surface shading lines are not surface ornamentation.
Molded concrete U-wall construction block employing a metal reinforcement cage having stem reinforcement portions with open apertures formed therein for multiple purposes