Choose between two places

Both Qinghai lake and Guanshan prairie is beautiful, now I have seven days to relax, which place should I choose? This is a big headache, because I do not want to spend only one day in Qinghai Lake and I might do not have too much time to use, and I know that Guanshan prairie is far less beautiful than the Qinghai Lake, so I have not made any desicion, below, I put those pictures of the two sites to let you choose which one you might go.
1 Guanshan prairie
2 Qinghai Lake