At the main gate you find a map of the compound.
If you are a visitor of Shanghai, don't miss to see places which are still authentic Chinese. :-)
The cache is located on the outer side of a small park. You do not need to leave the footpath.
The compound is accessible for everyone day and night, however, i recommend searching this cache during the day. The main gate has barriers to limit the access of cars, but you can walk through without any problem.
The box is big enough to leave trackables (if not super big)