Not the walls, but steps similar to what I have drawn in plan view so far Check out retaining wall projects from exceptionalstone.com!
Terraced backyard More
great idea! fire pit area built into hillside, retaining wall=seating area
backyard kids play area ideas | The steep gradient of this Double Bay garden rendered it inaccessible ...
inspo... backyard designs with terraces on hill slopes http://www.lushome.com/25-beautiful-hill-landscaping-ideas-terracing-inspirations/148719
backyard ideas...The San Francisco Envy Chain - NYTimes.com
This terraced garden, designed by Julian Tatlock Garden Design, made use of natural slopes to create a beautiful set of terraced plant beds.
We are doing this in our backyard - we already have the terraced steps and slope - just need to find a slide that's long enough...
Clever landscaping idea. Could do something similar along the side yard where wed like to reshape our slope and put a terraced garden and hot tub in.
Terracing Mosman Landscape Design: Outdoor Establishments