I'll be visiting Shenzhen and Shanghai in March, how far is the great wall from those locations?

Donald, visitors usually go to visit the sections in Beijing. It's about 820 miles (1318 kilometers) between Beijing and Shanghai if you take G trains, and 1500 miles (2400 kilometers) between BJ and Shenzhen by airconditioned train.

If it's your first time to visit the wall, then I think you might visit Badaling. The transportation is convenient. You can take bus no. 877 from Deshengmen to reach there.