PORTLAND — The Coast Guard, American Lighthouse Foundation and Maine Office of Tourism are sponsoring Maine Open Lighthouse Day.

Officials say the event on Saturday is the largest of its kind in the country.

All told, 23 Maine lighthouses will be open to the public. That includes some that are not normally accessible including Owls Head Light, Bug Light in South Portland, Monhegan Island Light, and the tower at West Quoddy Head Light.

Coast Guard Lt. David Bourbeau calls it a “unique opportunity to get an inside glimpse of some of Maine’s most beautiful and historic navigational landmarks.”