Twenty-five Maine lighthouses will be open to the public Saturday, Sept. 17 as part of the third annual Maine Open Lighthouse Day. The public is invited to visit and tour the towers and keeper’s houses of lighthouses from Biddeford to Lubec.

This event is the largest of its kind in the country, and is coordinated by the U.S. Coast Guard, in partnership with the Maine Office of Tourism and the American Lighthouse Foundation.

Most of the 25 ocean, river and island lighthouses will be open to visitors from 9 a.m. to 3 p.m. for guided or self-guided tours. The list of participating lights can be seen below.

Some lights that are not normally open to the public include Owls Head, Curtis Island in Camden Harbor, Dyce Head in Castine, Monhegan Island, Portland Breakwater and the tower at West Quoddy Head in Lubec. Some light stations may have limited accessibility or special restrictions.

“Open Lighthouse Day is a wonderful opportunity for the public to experience some of these important nautical landmarks in a way they may never have seen before,” said Lt. j.g. Terence Leahy, Waterways Management Division, Sector Northern New England, in a news release. “Even to this day, many lighthouses serve as navigational aids to keep mariners safe at sea.”

Participating lighthouses:

Bass Harbor Head Lighthouse – Bass Harbor on Mount Desert Island (land-based)

Browns Head Lighthouse – Vinalhaven Island (offshore)

Burnt Coat Harbor Lighthouse – Swan’s Island (offshore)

Burnt Island Lighthouse – entrance to Boothbay Harbor (offshore)

Curtis Island Lighthouse – entrance to Camden Harbor (offshore)

Deer Island Thorofare Lighthouse – Mark Island near Stonington (offshore)

Doubling Point Lighthouse – Arrowsic (land-based)

Dyce Head Lighthouse – Castine (land-based)

Fort Point Lighthouse – Cape Jellison near Stockton Springs (land-based)

Grindle Point Lighthouse – Islesboro (offshore)

Kennebec River Range Lights (two towers) – Arrowsic (land-based)

Little River Lighthouse – entrance to Cutler Harbor (offshore) 12 noon to 3:00 pm

Marshall Point Lighthouse – Port Clyde (land-based)

Monhegan Island Lighthouse – Monhegan Island (offshore) 11:00 am to 4:00 pm

Owls Head Lighthouse – Owls Head (land-based)

Pemaquid Point Lighthouse – Bristol (land-based)

Portland Breakwater Lighthouse (Bug Light) – South Portland (land-based)

Portland Head Lighthouse – Cape Elizabeth (land-based)

Rockland Breakwater Lighthouse – Rockland (land-based via a breakwater)

Seguin Island Lighthouse – near entrance to Kennebec River off Popham Beach (offshore) 11:00 am to 2:00 pm

Spring Point Lighthouse – South Portland (land-based via a breakwater)

Squirrel Point Lighthouse – Arrowsic (land-based)

West Quoddy Head Lighthouse – Lubec (land-based)

Wood Island Lighthouse – Biddeford Pool (offshore)

The Maine Lighthouse Museum in Rockland will also be open.