Have wanted to see Castle Island and the Harborwalk for a long time now. Easy to park. Disappointed at the trash and filth around Sullivan's, though we did get a soft serve ice cream. My daughter said that pigeons must be the seagulls of the city.... The playground was fine, the beach...well....you need surf shoes- it is more like post-snowstorm gravel. The walk around the fort is fine and the view of the busy harbor is great. You back up to the cargo terminal for the Port of Boston, there is a fishing pier, and quite noisy due to Logan flight path. Ample bathrooms. Had slightly higher hopes for this spot. Go see it then check it off your list.