Retaining wall for one side of dirt leading to shed

[Ken Tannenbaum1]

Leading up to a 16’ wide shed is a solid dirt ground “ramp” which levels out on one side but falls off n the other side. I’d like to flatten out the fall-off side with a retaining wall that runs from maybe three feet off the side of the shed at an angle of about 15 degrees and would run about 20feet. Could be stone or block about 3 1/2 ft high topped with something, not sure what. Any thoughts appreciated.