Happy Valley is a wildly popular national amusement park with locations around China. This park is separated into different zones (Shanghai Bund, Gold Mine Town, Happy Ocean etc) and features loads of attractions and rides, including the country’s first wooden roller coaster, the Fireball. The park closes during rain storms.
There's a free bus to Happy Valley from Sheshan metro. The No 9 bus (¥1) also runs there from Dongjing metro station.