Mentioned by Wildland Trekking
Smoky Mountains Waterfall Hiking Trails | Wildland Hiking Trails Guide
"At the 25-foot-high Grotto Falls, you can enjoy the unique experience of walking behind the falls, which can be a welcome refreshment on hot, humid summer days. The trail leading to the falls is beautiful as well, as it passes through old-growth forests and ecosystems and gives visitors opportunities to see animals such as black bears, elk and deer. To access the falls coming from Gatlinburg on the parkway, turn onto the Historic Natural Trail at traffic light #8, which will lead to Great Smoky Mountains National Park."