Retaining walls are needed in some landscape applications where soil needs to be held back from a hillside or held up to create more space.  Retaining walls can be constructed from concrete cast products as well as natural stone such as outcropping.  Sitting walls are typically installed around a paver patio for extra seating.  These seat walls can be constructed from cast concrete as well as natural stone.  Sitting walls can also be used as retaining walls in some instances.  Seat walls and retaining walls can also be outfitted with landscape lighting to illuminate the area around the wall.