The South Park Senior Center is a retirement home for the town's elderly. It is referred to in some instances as Shady Acres, an existing location in the show that serves the same purpose.
South Park: The Fractured But Whole[]
The South Park Senior Center is the main setting for The Samaritan Agenda mission, where Tupperware, Wonder Tweek and The New Kid are tasked to sing for the elderly. When the elderly discovered the New Kid's identity, the superheroes attempted to escape the senior center.