North River Wildlife Sanctuary, named for the state-designated Scenic River that winds along its northern boundary, serves as the base for South Shore Sanctuaries (which includes Daniel Webster and North Hill Marsh). 

The sanctuary's fields, oak forest, and salt marsh attract a wide variety of birds, and seals are often visible from the riverside platform. Programs and summer camps take place in and around the historic building.

Explore more than 2 miles of trails, including a universally accessible loop trail, at North River Wildlife Sanctuary in Marshfield. There is a boardwalk that takes you down to the edge of the North River and another that goes through the woods to Hannah Eames Brook where you may see flowering witch hazel, mink, or dragonflies.

River Loop Trail 
Length: 30.75 miles
Details: This trail circles an open field, offering opportunities to see eastern bluebirds, hunting red-tailed hawks soaring overhead, and a wide variety of butterflies feeding on native flowers. Two short spurs run off the River Loop Trail. The first goes over a boardwalk and through a wet red maple forest. The second goes to an observation platform set up for enjoying the activity and sounds of the North River.
Difficulty: Easy walk with a small incline. 

Woodland Loop Trail 
Length: 0.75 miles
Details: This trail, passes through a mixed forest where large oak, native witch hazel, and American holly trees provide habitat for wood thrush, several woodpecker species, and wild turkey. Red-backed salamanders also find homes here. A short spur goes to Hannah Eames Brook, named after an early resident.
Difficulty: Easy walk however you need to watch for exposed roots and rocks.

Hannah Eames Trail
Length: 0.5 miles
Details: As you cross over the brook, watch for water striders moving on the water’s surface. On the south side of the bridge, you’ll pass through a glen of lush ferns before walking through an old fieldstone wall. Watch for chipmunks and other animals who use the wall for shelter. The trail will travel upward through a mixed forest where red-tailed hawks sometimes nest. This is also a good place to stand quietly for a few minutes and search for deer. The loop trail will take you back for one more opportunity to enjoy the sounds of the brook before reconnecting with the Woodland Trail.
Difficulty: Easy walk but watch for the many roots and rocks, and slight incline.

Fern Loop Sensory Trail
Length: 0.25 miles
Details: This fully accessible all-persons trail leads through a wet red maple forest, over boardwalks, and through a leafy fern glen. Enjoy the coolness of the forest, the spring song of the wood thrush, and at least 5 different species of ferns on this loop trail.
Difficulty: Very easy, level walk.

The AllTrails website has a description and map of a hike at North River Wildlife Sanctuary.