Here is the part that surprises people: the Common has often played several roles at once. Over its history it has served as pastureland, burying ground, military encampment, theater for political action and public ground, sometimes all in the same era. Over nearly 400 years, it has witnessed grazing livestock, British encampments, abolitionist gatherings, speeches, food riots, concerts, militia mustering, protests, ice skating, ball games and public executions. That list reads like a summary of Boston's character, from the military and political dramas of the colonial period through the reform movements that followed, to everyday recreation. Throughout the Common and the Public Garden, markers identify sites of historical significance, so keep an eye out for them as you wander. The Common is also where Boston's best known walking route begins. The Freedom Trail starts here, winds through the historic North End and ends at the Bunker Hill Monument in Charlestown. It is a stroll of two and a half miles over easy terrain that links 16 significant historical sites, including museums, meeting houses and a ship. The Common itself was added to the National Register of Historic Places on July 12, 1972, and designated a National Historic Landmark district on February 27, 1987.