If you're looking for a comfortable, flexible tour, the Old Town Trolley might be right up your alley. This tour takes you through most of Boston, and has 17 designated stops where you can get on and off whenever it suits your fancy. The trollies are open-air and offer a number of good views and opportunities to take photos throughout the trip.

Tour begins: Tickets available in Faneuil Hall and the New England Aquarium
Cost and hours: $31.50 for a 2-Day Pass, $22.50 for a 1-day pass 12 and under are free; open 9 a.m. to 5 p.m. daily