Mystic Ruins (Sonic Chronicles: The Dark Brotherhood)

In Sonic Chronicles: The Dark Brotherhood, the Mystic Ruins again features as a game area, although the characters visit a more swamp-like section than those seen in Sonic Adventure. Mystic Ruins is home to many wild animals, such as Queen Wasps, Giant Millipedes and Colossal Worms. Toxic, malodorous) gases are emitted into the air by Procurator Shade's inter-dimensional Nocturnus forces, in a bid to clear the area of G.U.N. soldiers. The gas is only passable by Big the Cat, who is recruited into the party in this area.

Along with the crumbling Knuckles Clan ruins as seen in Sonic Adventure, the Mystic Ruins now hosts one of Doctor Robotnik's abandoned bases. Said base has been taken over by the Nocturnus forces, who are using it as a prison to hold Knuckles captive.

Later, Shadow the Hedgehog can be seen here when you begin your search for Dr. Eggman, and also unintentionally helps you on your quest in Chapter 3.