Keystone Hardscapes 88346 18" Anchor™ Highland Stone® Retaining Wall System Chicago. The Anchor™ Highland Stone® Retaining Wall System has been designed with the texture and look of natural stone. This unique three piece system offers a hand hewn facing that accommodates a stone like appearance. With the patented rear lip, setback and alignment are facilitated resulting in faster, more reliable construction. Available in blended earthtone colors, the Anchor™ Highland Stone® Retaining Wall System makes an architectural statement in segmental retaining wall systems.