Little Mark Island Monument

Eagle Island is an island in Maine's Casco Bay and the site of the summer home of the North Pole explorer Admiral Robert Peary (1856–1920). The island and home are preserved as the Eagle Island State Historic Site.

The Auburn–Harpswell Association Historic District encompasses a well-preserved enclave of summer residences built in the early 20th century in southern Harpswell, Maine. The district includes ten Shingle style houses, a Colonial Revival dining hall, and a Greek Revival meeting hall. The Auburn Colony, an exclusive company of businessmen from Auburn, Maine, was responsible for their development. The district was listed on the National Register of Historic Places in 1985.

Bailey Island Library Hall (locally just Library Hall) is a historic community building at 2167 Harpswell Island Road, on Bailey Island in Harpswell, Maine. Built in 1911–12, it has been a center of community life on the island since its construction, and is a notable architectural work of the New York City architectural firm Mann & MacNeille. Originally built to house a lending library and social hall, it now only serves the latter function. It was listed on the National Register of Historic Places on December 31, 2008.

Broad Sound is a passage north from Casco Bay through the islands northwest of Portland, Maine. It lies between Chebeague Island and Harpswell Neck.

Bailey Island is an island in Casco Bay, and a part of the town of Harpswell, in Cumberland County, Maine, United States. As of the 2000 census, the island had a year-round population of 400.

Harpswell Coastal Academy was a Charter School serving grades 5–12 with a campus located in Harpswell, Maine. The school was funded by the State of Maine. It was one of nine school districts in the state to receive federal funding under the Rethinking Remote Education Venture.

The Bailey Island Bridge (also called the Cribstone Bridge) is a historic bridge in the town of Harpswell within Cumberland County in the state of Maine.

Cliff Island is an island in Casco Bay, Maine, United States. It is part of the city of Portland. As of the 2000 census, the island had a year-round population of approximately 60 people. In the summer, the island's population grows to about 200, despite the fact that it is the only year-round inhabited island in Casco Bay with no paved roads. The ZIP Code for Cliff Island is 04019.In the early 20th century, the island's inns were a draw for summer tourists. There are no longer any hotels, but many homes are available for weekly rentals or longer. While there are no public services, residents enjoy a community hall, a tennis court, baseball field, and playground. The residents are served by a USPS Post Office, fire department, and one-room school for elementary grades. While the postal service has considered closing the office in the past, the islanders have managed to keep it in operation for six hours a day.

Chebeague Island is located in Casco Bay, an inlet of the Gulf of Maine. It was originally used as a fishing ground by Abenaki Native Americans. Also known as Great Chebeague (pronounced "sha-big") Island, today it is a town in Cumberland County, Maine, United States. It is located 10 miles (16 km) northeast of Portland, Maine. Chebeague Island is the largest island in Casco Bay that is not connected to the mainland by a bridge. The largest island is Sebascodegan, or "Great Island," which is part of the Town of Harpswell and connected to the mainland via a 100ft bridge. Chebeague Island is one of the twelve major islands of the Calendar Islands, a term that originated in 1700 with the report by the English military engineer Wolfgang William Römer, who claimed there were "as many islands as there are days in the year." As a corrective, the Maine State Historian Robert M. York stated there are "little more than two hundred islands" in Casco Bay.Chebeague Island was a part of the Town of Cumberland until July 1, 2007, when it seceded and became the Town of Chebeague Island. The Town of Chebeague Island includes seventeen islands and their adjacent waters. These include the islands of Bangs, Bates, Hope, Ministerial, Sand, Stave, Stockman, and the tiny Upper Green Islands. At the 2020 census, the town's year-round population was 396. The population is said to more than triple in the summer months. Chebeague Island is part of the Portland–South Portland–Biddeford, Maine Metropolitan Statistical Area.

The Chebeague Island Inn is located on Chebeague Island, Maine, United States. Situated in 2.5 acres (0.0039 sq mi), on South Road, near the northern tip of the island, the inn overlooks part of Casco Bay. Just beyond the western edge of the inn's property, Stone Wharf Landing is where the Chebeague Island Ferry, which runs to and from Cousins Island, berths on the island. The inn also overlooks a few holes of the island's nine-hole golf course. The inn, which has twenty-six rooms, was built in the 1880s, and was originally known as the Hillcrest Hotel. The inn burned down in the early 20th century and was rebuilt in the 1920s. It was given its current name in 2000, and was fully renovated in 2004. It is open between May and October.

Luckse Sound is a sound in Casco Bay, Maine, United States. Located between Long Island and Cliff Island, it is one of the deepest channels which separate inner Casco Bay from its outlying waters in the Gulf of Maine, after Portland Channel, Hussey Sound and Broad Sound.Ships were torpedoed in the sound during World War II.Today, the Casco Bay Mailboat passes through the sound.

The Great Chebeague Golf Club is a country club at 16 Stone Wharf Road on Chebeague Island, Maine. It has a nine-hole golf course on more than 28 acres (11 ha) on the north side of the island. Its clubhouse is a repurposed circa 1807 residence, which is probably one of the oldest buildings used for that purpose in the nation. The club was listed on the National Register of Historic Places in 2015.