A retaining wall system comprising an earth structure defining an earth surface, a wall system arranged on the earth surface, and a backfill structure arranged on the earth surface behind the wall system. The backfill structure comprises a base portion, a plurality of backfill members, and a cap portion. The base portion comprises at least one layer of loose backfill material. The plurality of backfill members are arranged in at least one course on top of the base portion. The cap portion comprises at least one layer of loose backfill material.