Lighthouse

 Thacher Island National Wildlife Refuge is home to herring and great black-backed gulls.  The refuge serves as a stopover site for songbirds and other migrants to rest and feed during seasonal migration.  Off-shore habitats are used by seals, waterfowl, loons, grebes, cormorants and alcids.

There are two lighthouses are only hundreds of feet apart on Thatcher Island, which makes it unique to New England.  The only other twin light house is Twin Lights of the Navesink in New Jersey.