Reference

The Couple's Retreat Garden, also known as Ou Yuan, covers an area of approximately 0.8 hectares (8,000 square meters) including the central residential area and the garden zones. This does not explicitly mention the size of the buffer zone specific to the Couple's Retreat Garden. However, buffer zones for heritage sites typically include additional protections surrounding the main site to preserve its integrity and ambiance. According to various sources, the total area might match or slightly exceed the aforementioned sizes due to these additional protective measures.

For more detailed visual representation and further information, these resources can be helpful:

• Suzhou Government English Page
• Travel China Guide on Couple's Retreat Garden
• UNESCO World Heritage Centre buffer zone images and documents: UNESCO Document

Here are some relevant images of the Couple's Retreat Garden: