New Hampshire State Route 1A runs north-south along the Atlantic coast of Rockingham County. It runs from the Massachusetts/New Hampshire State Line, near Seabrook Beach, to U.S. Rt. 1, at Portsmouth. NH St Rt 1A passes through the following towns in Rockingham County. Seabrook Beach
Great Boars Head Little Boars Head Rye Beach Rye North Beach Wallis Sands Portsmouth NH St Rt 1A is not multi-plexed in Rockingham County. NH St Rt 1A intersects the following highways in Rockingham County. New Hampshire State Route 286, at Seabrook Beach.