Mass. Gen. Laws ch. 45, § 11

In a city which by a vote of its city council, or in a town which by vote of a town meeting, accepts this section, or has accepted corresponding provisions of earlier laws, the park commissioners may, in accordance with section thirty-seven of chapter eighty-two, establish a building line distant at no point more than twenty-five feet from any exterior line of a way under their control or the part of a public way on which a park abuts; and the extreme height to which buildings upon such ways may be erected shall be seventy feet exclusive of such steeples, towers, domes, cornices, parapets, balustrades, sculptured ornaments, chimneys and roofs as such board may approve.