Stardew Valley is a farm life simulator where you fight enemies, make friends, and grow your village. Alongside numerous activities, the evergreen town of Pelican Town holds many secrets, including one hidden beneath the surface the sewers. To access this hidden area, you must obtain a key called a Rusty Key. However, in order to get your hands on it, youll need to work your way around and become the biggest contributor to the Pelican Town Museum. This guide explains everything you need to know about it.