Mount Greylock Summit Tower, Massachusetts

This granite tower was originally destined to be a lighthouse on the Charles River estuary in Boston, but was instead hauled up to the top of Mount Greylock, Massachusetts' highest peak (3,491 feet), in 1932. The 92-foot-tall tower as originally conceived, had an observation deck and a glass sphere at the top containing six 1,500-watt searchlights - the most powerful light in the state at the time of construction. The tower is not the highest structure in the state, however. A 200-foot tall broadcast transmission mast was built near the tower by General Electric in the early 1950's. It is used by various radio and television stations. Mount Greylock is one of the 28 of the 50 highest points in the 50 states that are accessible by car.