View from highway Driving East. Buzzards Bay to Rock Harbour The southernmost tip of the Commonwealth of Massachusetts stretches approximately 100 miles out into the Atlantic Ocean. This wonderful peninsula is known as Cape Cod - the north side shore opens to the cool waters of Massachusetts Bay while the southern beaches reach to the warm and gentle waters of Nantucket Sound. Centrally situated is the Town of Barnstable with shorefront on both north and south coasts.