The East Bay Hills refer to a 'fault ridge' of ancient rock on the south side of the East Bay of the Bras d'Or Lake, located on Cape Breton Island, Canada, and are an extension of the Appalachian mountain chain. The East Bay Hills lie in Cape Breton County. The East Bay Hills rise to little more than , forming low ridges in an otherwise lowland landscape. These hill are largely uninhabited (by humans), and include the highest elevation point on Cape Breton Island south of the Bras d'Or Lake at Sgurra Bhreac with a commanding view of the Mira area and Atlantic Ocean to the south. Geology and landscape development The East Bay Hills are an elongated block of Precambrian rocks and is composed of two rock types: primarily volcanic deposits of the Fourchu Group (ash and lava interleaved with marine sediments), but also granites. They are elongated northeast–southwest in accordance with the same prevailing trend of faults which dominates the geological structures of the North Bras d'Or Uplands. The southeastern margins are also faulted, in this case bringing the resistant Precambrian strata against late Carboniferous sandstones and siltstones. On the northeastern side the contact is with easily eroded Carboniferous Windsor Group strata, which were deposited directly against the blocks when they stood as islands in the Carboniferous Sea. In form and structure the relief and elevations of the East Bay Hills reflect not only their geological setting, surrounded by rocks of varying resistance, but also their position on the low side of the planation surface. Precambrian rocks of equivalent resistance have created dominant uplands further north in Cape Breton, but here, where there was little uplift during the Tertiary, there was also minimal rejuvenation of erosional action and limited exposure of this hard core of old rocks. The steepest slopes are found on the northwest side of the East Bay Hills, where soft Windsor Group rocks form a narrow band along the shore. The valley of Breac Brook, at the north end of East Bay Hills, appears to be an ancient coastal valley which was filled by Windsor Group deposits and is now being exhumed. The fault line on the southeastern margin can be seen in some areas (e.g., northeast of Oban) but in general does not form a prominent scarp slope. In this part of Cape Breton south of Bras d'Or Lake, glaciation more than geological structure