Mackworth Island is an approximately 100-acre (40 ha) island in Casco Bay, Maine, United States. Politically, it is part of the town of Falmouth, which is adjacent to Portland. In 1631, Sir Ferdinando Gorges, who first attempted to colonize Maine, gifted the island to Arthur Mackworth, his deputy in Casco Bay, and the island has retained his name. A causeway, which carries the traffic of Andrews Avenue, connects the island to Mackworth Point on the mainland. Visitors to the island must pass a state park entrance tollhouse and pay an entrance fee; cars can enter the island, but parking is limited. There is a footpath around the perimeter of the island with views of Falmouth, Portland, and other islands surrounding the bay. The island is heavily wooded and one portion of those woods is dedicated to "Fairy Houses" which are constructed by visitors using natural materials found on the island. Although most areas of the island are State Park lands, there is a school area that is not open to the public. The island is also home to the Governor Baxter Dog Memorial, a pet cemetery where fourteen of the former governor's Irish Setters and one of his horses were laid to rest, accompanied by two bronze markers and a gravestone, all enclosed by a circular stone wall.