Good day Traveling to Beijing in September

We have 13 days in China with my family landing in Beijing the traveling to Datong
Then to xinzhou
Then to Taiyuan.
Need help to find 2 best places to see on the way back to Beijing either along the coast or alternative.
We have 4 days to work with. We would also like to see the Great Wall on the way back
We enjoy culture, food and architecture.
Can You advise
Kind regards