Good idea if you have rock solid ground that is hard to dig up. If you don't cover the holes you can use them for herbs & annuals. also lined with weed barrier cloth & used rebar in several places for stability. It makes maintenence super easy.
DIY - Homemade Gabion wall ie rocks encased in wire baskets and used as a retaining wall - creates a dramatic feature in a garden. No directions on link. Nice someone figured out how to landscape with river rock. I swear they grow!