Portland Head Light - Cape Elizabeth, Maine:Portland Head Light in Cape Elizabeth, Maine on May 21st, 2015. Portland Head Light is a historic lighthouse in Cape Elizabeth, Maine. The light station sits on a head of land at the entrance of the primary shipping channel into Portland Harbor, which is within Casco Bay in the Gulf of Maine. Completed in 1791, it is the oldest lighthouse in the state of Maine. The light station is automated, and the tower, beacon, and foghorn are maintained by the United States Coast Guard, while the former lighthouse keepers' house is a maritime museum within Fort Williams Park.