from shanghai to great wall, how many hours will it take ?

Mick, it takes around 11.5 hours by D trains and 5 hours by G trains from Shanghai to Beijing South Railway Station. Then you need to take subway line 4 to reach Xizhimen Station. It takes around 30 minutes. Getting out of the Exit A of Xizhimen Station, you walk to Beijing North Railway Station to take S2 train to reach Badaling. It takes 1 hour and 20 minutes. You can calculate how many hours you need to visit Badaling from Shanghai.

thanks steven from Nauru