New Hampshire has a short Atlantic coastline — only 18 miles long — between Maine and Massachusetts, but that strip of shore has two lighthouses, one of which is the Portsmouth Harbor Lighthouse.
The lighthouse protects the harbor of Portsmouth, which is on the Piscataqua River and is New Hampshire’s only deep water port. The first beacon was built in 1771 and was the 10th of 11 light stations built before the Revolutionary War. In 1878, the current 48-foot cast iron, brick-lined tower was constructed. It has a fourth-order Fresnel lens that is covered with a green acrylic cylinder.