Serenity Valley Convalescent Home is a nursing/hospital facility which is located in Davenport, Iowa.
- Doctor Green was actually a Horseman named Pestilence pretending to be a doctor in order to experiment on patients. Before infecting Celeste with multiple deadly diseases, he tells her that she's his "favorite patient".
- Doctor Green's assistant helped Doctor Green (aka Pestilence) by watching for Sam and Dean. She also managed some other patients.
- Celeste was a patient of this nursing home.