With Cape Ann’s rocky shores and heavy fishing industry, the area is a haven for lighthouses. A few are accessible by land, while others have to be seen from a distance on the water. Twin lighthouses appear on Thacher Island, and have been a viewpoint for those on land since 1771. The 45-foot towers are the only surviving multiple lights in the U.S. Eastern Point Lighthouse marks the entrance to Gloucester’s Eastern Point, standing at 36 feet since 1890. Annisquam Harbor Lighthouse was erected in 1801 to mark the entrance to the Annisquam River. Ten Pound Island Lighthouse is a 30-foot structure providing navigation into Gloucester’s inner harbor. Straightsmouth Island Lighthouse marks the entrance to Rockport Harbor.