Be careful!
In today's Beijing, there are still a lot of illegal tour buses to the Great Wall, once you get on it, you will start a terrible trip.

Their salesmen always deliver a small card to travelers for Great Wall tour by standing on the street, Tian'anmen Square, or the entrance of Forbidden City, their way to attract the travelers is their unbelievable low price, but if you get on their bus to go to the Great Wall, they will let you to pay additional sites again and again, even the Great Wall is not real Badaling section, so , we strongly recommend you do not take their card if you happen to meet them. Meanwhile, it's easy way to discover their tour bus is illegal, in Beijing, there is a " B" on the legal tour bus code , if not, it will be possible that you get on a "illigal tour bus"