The Old North Bridge is a historic site located in Concord, Massachusetts. It is famous for being the location of the first significant battle of the American Revolutionary War on April 19, 1775. The bridge spans the Concord River and was part of the original road connecting Concord to Lincoln. The bridge is often associated with the phrase "the shot heard 'round the world," marking the start of open conflict between the American colonists and British troops. Today, the Old North Bridge is preserved as part of the Minute Man National Historical Park, attracting visitors interested in American history.