The Great Wall : Mutianyu
Mutianyu is 90 km northeast of Beijing. It was a good alternative to Badaling, but this place has become as crowded as the other. The environment is pretty wild with steep hills (up to 45° slope!) and forests. The bus does not lead to the wall and you have to walk half an hour.
Take teh bus No. 916 from Dongzhimen bus station to Huairou, the nearest town (approximately 1 hour drive). From there, you have to change buses to Matianyu. Otherwise, there is the solution of tourist minibuses depart from Qianmen, south of Tiananmen Square. For the return, check well for the last departure time (5:30 p.m.?).