New Hampshire's Abandoned Military Fort Is Now A Historic Ruin Inside A State Park With Trails And Ocean Views

Just a 10-minute drive south of Portsmouth on the edge of Odiorne Point State Park, the abandoned remains of Fort Dearborn lie hidden in the woods, surrounded by coastal trails and ocean views. Not to be confused with Fort Dearborn in Chicago, this historic New Hampshire ruin attracts explorers who enjoy discovering derelict military buildings being taken back by nature. Named after General Henry Dearborn, the base was built during World War II to protect Portsmouth's submarine shipyard from potential German U-boat attacks. Although the fort was never used, the threat to the Eastern Seaboard was real.

Fort Dearborn was decommissioned in 1948, but some of the old military relics can still be seen today, including a couple of gun batteries and a few pillboxes. Invasive plants were used to conceal the fort during the war years, and this rampant vegetation continues to give the place a wild and abandoned feel. It's a good idea to take some bug spray, as mosquitoes can be rife in these dense woods. As you wander around the historic fort, you'll see the concrete structures poking out of the foliage, some of which are now covered with vibrant graffiti.

One of the most prominent features of Fort Dearborn is Battery 204. It's just a short walk from the parking lot and was once home to an observation tower, built for spotting enemy ships. The danger passed long ago, but the scenery remains, and as one explorer on Abandoned Wonders writes, if you climb on top of the battery, you'll be "treated with a wonderful view of the Atlantic seacoast." Similar panoramas can be enjoyed from New Hampshire's only standing WWII watchtower at Pulpit Rock, which is a 2-minute drive south along the coast.

The U.S. is home to many once-thriving military sites that have been transformed into scenic escapes. Just like this deactivated military base in Washington, Fort Dearborn is surrounded by ocean views and nature. Odiorne Point State Park has a network of trails to explore, with several routes to choose from. Some trails run alongside the coastal dunes and salt marshes, while others traverse dense woods and wetlands, passing abandoned military relics on the way.

If you want an easy circular walk with coastal vistas and fort ruins, there's a scenic 2.8-mile loop trail that takes you past the remains of Battery Seaman, as well as the stone jetty at Frost Point and the rocky shoreline at Odiorne Point. As one Komoot user mentions, there are "excellent views of the lighthouses and islands in the bay" from the latter. The hike is relatively flat and takes a little over an hour. For a shorter stroll, there's a circular route that's less than a mile long, conveniently starting and finishing at the Seacoast Science Center near the parking area. It follows the coast past the intriguingly named Pirate's Cove, before taking you to the Founder's Monument, which commemorates the first group of English settlers who landed here in 1623.

You can plan your route using this trail map produced by the Seacoast Science Center. It's advisable to keep an eye on the state park website for current trail closures, and you should always check the tide times before setting out, as parts of one coastal path are sometimes inaccessible at high tide. There is a small entry fee to access Odiorne State Park, and guests will find a picnic area and seasonal restrooms if they want to make a day of it.