This was a great place to visit with our kids and their grandparents. Nice visitor center with exhibits and a helpful volunteer staffing it. Easy trail (Butterfly Trail) connects to WWII bunker which offers great views of the marsh, barrier island and ocean from the top (take the path to the right and climb the stairs after you pass through the bunker--note that there are lots of stairs to climb to get to the top). Finally, the trail ends with a great view of the marsh where we saw lots of birds, fish, etc.
The refuge also has a boat and kayak ramp which we saw, but did not use.