Boston's Children's Museum sits on the Fort Point Channel waterfront and is one of the oldest and best children's museums in the United States. Interactive exhibits range from a full-scale cut-away city street where kids can play at road-digging to a Japanese house transplanted from Kyoto and hands-on explorations of science, art, and music. The "How Does an Orchestra Work?" exhibit is a perennial favourite.
Plan for crowds on rainy days and school holidays — the museum handles them well enough but it does get loud. Admission is $1 on Friday evenings from 5–9pm, making it an excellent budget option for families staying in the city. The waterfront location, a short walk from South Station, also makes it easy to combine with a stroll along the Harborwalk.