Abstract: A block useful for constructing retaining walls for gardens, has two bottom lugs or knobs, bracketing an internal cavity. The cavity may be filled with soil. In forming a wall, the upper row of blocks is rearwardly onset from the lower row of blocks, whereby the lugs of the blocks of the upper row abutting the back surfaces of the blocks of the lower row.

Abstract: A block for forming a retaining wall comprising a generally parallelepiped body with front, rear, top, bottom and side surfaces and a central internal cavity with internal walls. Integrally formed protruding knobs are formed on the bottom surface adjacent the front surface and are positioned for protruding into the central cavity of at least one other block in a wall formed from the blocks. The protruding knobs are adapted to abut the internal walls of the open cavity to position the block in the retaining wall. A wall construction using the blocks is provided.