Belle Isle Marsh Reservation in East Boston preserves about 350 acres of coastal wetlands along the edge of Boston, Revere, and Winthrop, including the largest remaining salt marsh in the Boston area. Within a heavily urbanized setting, it protects a rich habitat for saltmarsh plants, marine life, and birds, making it one of the region’s most important wetland environments. Its history reaches to the colonial period, when Belle Isle was an island granted in 1628 to William Brereton and later known by several names before becoming Belle Isle. Part of the former island became Orient Heights, while much of the rest survives as the marsh preserved today.