Seven Islands State Birding Park

Tubing outfitter on the Little River in Townsend with two outposts, tube rentals, shuttle service, and riverside picnic areas. It also runs whitewater rafting trips from Hartford.

Zip line tour just outside Gatlinburg, across the road from Great Smoky Mountains National Park, with a guided mountaintop course of about two hours. Reservations are required.

Knox County park and state natural area in Corryton with trails to the highest point in Knox County and views of the Smokies and Cumberland Plateau.

Nonprofit nature center on more than 320 acres in South Knoxville with hiking and biking trails, Mead's Quarry for paddling and swimming, a visitor center, and animal ambassadors. Grounds and trails are free to visit.

Treetop adventure park at Ijams Nature Center with zip lines, aerial obstacle courses, and Navitat at Night tours. Reservations are recommended and tours are weather dependent.

Kayak, canoe, and paddleboard rental outfitter with a location on Melton Hill Lake in Oak Ridge and a second location at Norris Lake across from Norris Dam Marina.

Independent outdoor retailer on Sutherland Avenue for more than 40 years, selling biking, running, camping, climbing, and paddling gear. It also runs seasonal kayak and paddleboard rentals at Augusta Quarry, Concord Park, and Ijams Mead's Quarry.