|| || || John Hancock Tower, 200 Clarendon St., Boston, MA, (617) 572-6429. This building is hard to miss -- it's the tallest in New England. At first, it seemed as if Hancock's bid to spite the towering Prudential building was going to end up as a pile of glass on the sidewalk. Now the public is welcome to visit the top of this impressive piece of I.M. Pei architecture and view the city. Exhibits on the observation level include a light-and-sound show about Boston in 1775 and films about the history and architecture of the city. The view is spectacular, especially at night, and affords the perfect opportunity to examine the Emerald Necklace layout from above. Open 9 a.m. to 11 p.m. Last ticket sold at 10 p.m. Tickets $6, $4 for seniors and children five through 17, free for children under 5.