Travel to the Charlestown Navy Yard located in Charlestown, Massachusetts, a borough in the northern section of Boston, near the harbor.
Park in the Nautica Garage public parking area at 88 Constitution Road if you are traveling by car, then walk across the street to the National Park Visitor Center, which is the entrance to the ship.
Enter the USS Constitution ship exhibit through the Visitor Center building. This building also includes a small display of model ships and a gift shop.
Cross the paved lot behind the Visitor Center building when you exit and access the ship by walking up the gangplank to the right of the giant anchor at the water's edge. You do not need a guide to tour the ship but you may find it more interesting to wait for one of guided tours at the back of the Visitor Center where you exited to learn more about the ship. Navy personnel on the ship can answer any questions you have if you come on board without a guide.