Don’t just assume that a sloped area is pretty much useless. Sure, you can’t play ball on a hill, or sit around a fire pit on a hill, but don’t give up that quickly!  

Consider terracing that slope. Terraces are simply a way to make one or more level areas on a slope by creating a series of retaining walls and flat areas. This terraced patio has a beautiful curved stone staircase and a patio in the main level area.  Within this patio area is a fire pit and some plantings. Then, another stone staircase with another retaining wall get you to the upper level.  

Now, not only is there useable space on a one-unusable slope, but just look at it! What a statement! This terraced patio looks out over the mountains of New Hampshire. It makes this back yard a real stand-out.