Knuckles' Hangout is a dark and murky cave with moss growing there. The only light sources are a hole in the roof and a burning torch. The furniture are made of rock and include a table, shelf and bench. Weightlifting gear can be found around the place. The walls also have purple crystal clusters.
In Sonic Boom: Shattered Crystal, Knuckles' Hangout is one of the locations that can be visited on the World Map of Scrapyard. Although Knuckles' Hangout can be accessed from when first arriving at Scrapyard, it is first until after the player has completed the Scrapyard leve that Knuckles appears in this location.
After Knuckles begins appearing in this location, the player can play a mini-game called "Knuckles' Workout" in Knuckles' Hangout once every 24 hours. In this mini-game, the player must rapidly press and to make Knuckles punch a punching bag with Sonic's aid, thereby filling up a gauge on the punching back. Once the gauge is full, the player will earn a Token.
- Contrast to popular belief, Knuckles' Hangout is not Knuckles' residence as Bill Freiberger has confirmed in an interview that Knuckles is a wanderer who lives in nature.
- Knuckles' Hangout is the only residence belonging to Team Sonic which has not appeared in any media outside of Sonic Boom: Shattered Crystal.