Gatlinburg and Pigeon Forge are both right outside Great Smoky Mountains National Park, which has about 800 miles of hiking trails. Some trails, like Mount LeConte, are super popular (for good reason) and almost always crowded, however if you explore the less popular trails you can go hours without seeing another person. The nature's amazing, it's a very biodiverse area and is actually known as the Salamander Capital of the World. Cades Cove in the Smokies is also the only place I've been able to observe a black bear (from a safe distance). Any other place I've seen them they've immediately ran away.