This 90-minute tour, hosted by Charles Riverboat Company, offers spectacular views of historic and contemporary architecture along Boston Harbor, the Charles River Locks, and the Charles River basin. The tour is led by Boston By Foot guides and is co-sponsored by BSA Space, a center for architecture and design--includes landmarks such as Marriott's Custom House, the Prudential Building, and the Hancock tower, as well as cutting-edge contemporary design by today's top architects. These are simply the best waterfront views of Boston and Cambridge. Tours depart from the CambridgeSide Galleria (100 Cambridgeside Place, Cambridge) Memorial Day through Columbus Day (May 27 through October 14, 2013). Tours leave at 9:30 am on Friday, Saturday, and Sunday; and 2:30 pm on Saturday. The cost is $25 for adults and $20 for BSA and Boston By Foot members, children, seniors, and students.