Well, it is easy to be found. Near the entrace of the wall, on the wall, you can see the vendors all most everywhere, of course, I mean Badaling Great Wall. You can select among a variety of interesting Great Wall souvenirs from T-shirts, wooden carvings, hats to cups. I bought a piece of Hao Han Jian (wooden pieces where your name is written and you are titled "real man"). It's funny!