Great Meadows National Wildlife Refuge

The Great Meadows National Wildlife Refuge is a 12-mile-long river wetlands conservation area, in two major parcels, stretching from the towns of Billerica, Massachusetts to Wayland, Massachusetts, along the Concord River and Sudbury River.

Part of the National Wildlife Refuge system, the park is a popular destination for bird watchers and tourists. About 85 percent of the refuge's 3,600 acres is freshwater wetlands.

Source: Wikipedia