Badaling or Mutianyu

For your reference, both of Badaling and Mutianyu Great Wall are interesting. Badaling is more famous but Mutianyu is much quieter due to the less tourists. If you have children or elderly people, I would recommend Mutianyu as the gentle slope there make it easier and safer to climb. Besides, usually there is no need to take cable car at Badaling Great Wall, but you can take round trip cable car at Mutianyu.