The Freedom Trail connects sixteen historic sites spread across downtown Boston: the Old South Meeting House where the Boston Tea Party was organized, Faneuil Hall, Paul Revere's House, the USS Constitution — the world's oldest commissioned naval vessel still afloat — and the Bunker Hill Monument commemorating the 1775 battle where Colonial forces proved they could stand against British Regulars. The park is unusual in that most of its units are urban buildings rather than open landscape.