The Upper Garden with 'Ha-Ha' wall: One side of the sinuous retaining stone wall is faced with stone, the other face sloped and turfed, forms a green pool for the upper garden. The ha-ha wall backed by Annabelle Hydrangeas conceals the driveway from sight and extends the view to the lower garden as one looks out from the house through the Zelkovas.They are planted between the hydrangeas and act as a first buffer to the busy street set behind the Lower Garden. Photo credit: ROGER FOLEY