a few hours to kill in guangzhou

I will be having a 5hour stop over at GZ on my way to Europe. I will be with my 4year old. I'm wondering if there is any sight seeing options, not too stressful as we will be tired, for me and my son, not too expensive and easy access back to the airport to catch my flight. I will say have 3hours to kill time. are there say tours from the airport that look around the city and back in a couple hours or so?