Just a short trip from Carolina Beach SP is one of the only NC parks with access to the coast- Fort Fisher State Recreation Area. The park contains an intact bunker from the civil war, loggerhead turtle nests, 4WD access along the beach, and a basin trail through the park's ecosystems .
Just down the road is a historic site, where you can walk around the remains of the fort from the civil war. Also, nearby is one of the North Carolina aquariums, where I stopped before visiting the park. The albino alligator was worth the visit for me.
While at the park, I hiked down the relatively short basin trail, past the bunker, and out to the observation deck to look out on the marshlands and the cape fear river. This is a great place to watch and take pictures of wildlife. I definitely recommend either driving the 4WD road or hiking the trail to get the full experience at this park.