Cobblestone – This sharply sloped hillside was carefully engineered with numerous cobblestone retaining walls to hold the soil and hillside behind it. Steep cobble stairs wind along the different terraced levels which contains mostly Mediterranean climate plantings, attractive for viewing from the house or patio above or below.
Flat wall rock-This beautiful rock wall and staircase is made using flat wall rock. I love the stepped capped edging along the stairs, and the gentle rounded curve of the wall above.
PS: Even though this book goes back a few years (1976) it has all you need to know about building your own stone retaining wall. Check it out – Building Stone Walls