For a respite from the city's noise and smog, head out to She Shan. The 100m hill is a blissful retreat and an interesting cultural destination as well. European missionaries set up a small chapel here in the 1850s which was transformed into the She Shan Basilica in 1935. You'll also find a Jesuit Observatory on the hill, which, among other things, features the Han Dynasty's earthquake monitoring device, made up of two dragon heads and a pendulum.
If you get swept up in the peace and quiet of the area, simply stay the night at the luxurious Le Meridien: http://ow.ly/t7nCY
The hotel is an oasis in Shanghai's summer heat with a man-made beach, a golf course, and a fantastic weekend brunch.
How to get here: take line 9 to Sheshan station and from there, you can either walk ~30 minutes to the mountain or take a 14RMB taxi ride.