Seven of the sites along the Freedom Trail , along with the additional site of Dorchester Heights in South Boston , have also been incorporated into Boston National Historical Park (Charlestown Navy Yard, Charlestown, 617/242-5642 or 617/242-5601, www.nps.gov/bost ).
Boston National Historical Park has visitors centers at the USS Constitution,  Bunker Hill , and 15 State Street, across from the Old State House . From that site, rangers lead 90 minute tours (2 p.m. Mon.–Fri., 10 a.m., 2 p.m., and 3 p.m. Sat.–Sun. mid-Apr.–mid-June; 10 a.m., 2 p.m., and 3 p.m. daily mid-June–Aug.) that take in five sites along the Freedom Trail.
The rangers are not quite as entertaining as the costumed actors from the Freedom Trail Foundation, but their tours have the additional appeal of being free.