The Couple's Retreat Garden or Ouyuan Garden is located on Xiaoxinqiao Lane, east of Suzhou City. It was listed as National Key Cultural Relics Protection Unit by the State Council in 2001, and in November 2001, it was recorded on the list of the world heritage by UESCO.
The Couple's Retreat Garden faces water on three sides and the street on one side. It has a total area of 8,000 square meters. The garden is unique in layout. The residential building stands in the center and flanked by an east and west garden. The residential part and gardens are connected by a sequence of multi-storied buildings. The residence area is in four yards and both the front and back gates are leading to river ports. The eastern garden is where Sheyuan Garden was originally constructed. It is centralized on the rockery, supplemented by the pool. Pavilions, terraces, buildings and pagodas are constructed around the pool. The main architecture is the multi-eave buildings which are called “the Chengqu Thatched Cottage”. It is the place the garden owner meets and entertains the guest. The eastern peak is towering and steep, with a cliff upon the pond. Dozens of flowers and trees are planted there, denoting forest delight; the western rockery is lower and serene, serving as the comparison of the main peak. It is one of the rare and precious Yellowstone Rockeries in Suzhou.
On the east of the rockery there is a pond called Moon Mirroring pond. A pavilion called Shanshui Pavilion is constructed to the south of the pond. There is a catalpa wood floor cover dating back to the Ming Dynasty, about 4 meters wide and 3.5 meters high. The carving "three friends in chilly weather"-the pine, the Bamboo and the plum, superbly exquisite, ranks first in Suzhou classical garden in terms of the size. The western garden takes the study the Zhilao House as the center, dividing the garden into two yards. In the front yard, there is a lake stone rookery snaking away, and at the back yard, a flower bed built with lake stones. Standing north is the books depository.