Alpenstein Alpenstein is the new smooth faced" retaining wall system; ideally suited for building terraced, plantable, landscapes. These one piece modularly designed units, are easy to place and appropriate for residential and commercial applications. Alpenstein doesn't just hold the earth back, it's actually embedded into it. Because minimal spacing is permitted between the units, the wall can be built straight or curved. Soil and plants can be introduced between the units and the greenery can be allowed to overtake the wall. Their root systems actually aid in wall stabilization! The unique design of Alpenstein allows for the natural flow of run-off water, rather than just diverting it. Alpenstein is the one true "green" wall. Site designed by