Casco Bay in Portland is dotted with over 200 beautiful islands. Peaks Island and Long Island are the most populated. Each island has its own personality and history. The islands accessible year round are Cliff Island, Chebeaque Island, Long Island, Peaks Island, Little Diamond and Great Diamond Islands. Casco Bay Lines ferry is the most popular means of transportation to and from the islands.
World War II left a big footprint on the Casco Islands. In 1942, the United States installed military reservations on Cape Elizabeth, Peaks Island, Jewel Island, Long Island and Bailey Island, and the islands were a hotbed of military activity. There were 58 military structures on Peaks Island. In 1940, U-boats patrolled the Atlantic Ocean in deadly packs sinking 4,407 Allied ships. Casco Bay played a very important role in protecting the coast, providing ships, hunting submarines and mounting the invasion. At the end of the war, the abandoned bunkers were renovated for new uses or are now landmarks.
