A big CIEE group went up to the northeast side of Beijing to see the Great Wall at Si Ma Tai, one of the more remote, less touristy and more cool sections of the great wall. It took about 2 and a half hours to get there, we had about 2 and a half hours on the wall, and then about 2 and a half hours to get back. It was a good day, could have been less hazy, but you can't complain about that kind of thing near Beijing, really.