Thacher Island Twin Lights

A National Historic Landmark
White light flashing five times at 20 second intervals.

Tacher Island's Twin Lights

Photo by Coastal Exposure

Also known as Cape Ann Light Station, the Twin Lights are the only surviving multiple lights on the coasts of the United States. The original 45-foot towers were constructed and lit in (1771 or 1789), making them among the oldest of America’s lighthouses. The stout 124-foot granite towers (with a focal plane of 166 feet) seen today replaced the original lights in 1861. The two towers, North and South, were constructed and placed so that when a ship puts sights on both towers, they point to true north, allowing sailors to check and adjust their compasses.

The Thacher Island Association provides a free boat service from Rockport Harbor to the island during the summer, with advance reservations. For more information visit

Twin Lights, Rockport

Photo by Boston Drone Works

Thacher's Island Twin Lights

Boston Drone Works

Rockport Lighthouse

Photo by Dwight Hebert

Rockport Twin Lights

Photo by Dwight Hebert