Flowers birds and lights The Plum Island Lighthouse is located right on the very northern part of Plum Island and was built back in 1898. This is a dangerous place that have taken many ships and people and the very first light on this spot was construction in 1788. The present lighthouse is a classic design. Only 35 feet tall, it still has the original 4th order Fresnel Lens and was fully automated in in 1951. Nothing fancy or unique, the white tower serves just to hold the lens and light up. The lighthouse is open on occasion during the summer and the grounds are always available to the public. The whole area is great for bird watching and the lighthouse grounds has some purple martin houses. It’s great to watch the little birds scoot around and catch the very numerous bugs right out of the air. Plum Island is a great place to visit and the lighthouse and grounds are beautiful. Great views of the wild ocean are only steps away and the little purple martins will help keep the bugs away.