In Sūzhōu we started by visiting the Humble Administrator's Garden, built by a civil servant in the 1500's. He could afford to built such a nice complex of streams, buildings, and bamboo lined walkways because he embezzled the money and then retired!
After that we drove over to Ruiguang Pagoda, which is near the only remaining section of the city gate. The gate featured a double set of doors that could slide up and down, with a courtyard in between. In the old days, the city guards would let you in, shut both doors, and then verify you were allowed to continue in.