Add cap blocks to the top row of a block or stone retaining wall. You can add a layer of masonry adhesive to hold them in place, then back fill. Or you can backfill as you go, then add the cap. Either (Patio Step Retaining Wall)
Retaining walls can add beauty, functionality, and value to your landscape. Featured: Bayfield retaining wall by Basalite. Love this look for raised beds on north side of house.
Capped wall / Building an interlocking retaining wall in yard