I just came back from Beijing. Beware if you decided to join a one day trip to the Great Wall and Ming Tomb. Be sure to ask if there are any other places the tour guide will bring you to that you have to pay extra. I join an one day trip to the Great Wall and Ming Tomb that said to cost 100RMB. I thought it's reasonable. But when I got on the bus, the tour guide collected a mandatory fees of 30RMB for a sliding car up to the Great Wall. It was said to be of safety reasons. In addition, she also forced everyone to pay an extra 40RMB to go into a Wax Museum that showed the history of Ming Dynasty. She said it bluntly that it was the only way she could make money from this trip. So, be sure to ask before you sign up for any trip!!