The School House Gap Trail is a short trail of around two miles that branches to many different trails. This trail is also one of the few trails where Horseback riding is allowed in the Great Smoky Mountain National Park.
The "Secret Trail" is called White Oak Sinks, which splits off from School House about half way thru. It leads to a small waterfall that drops into a sink which is also a bat cave. This section of trail is no longer serviced by the park service other than to set bear and wild pig traps.
If you ever visit the Smokies during the Spring Wildflower festivals this is one of the places a guided tour will take you on.
I have been on this trail three times and have now twice had very up close bear encounters. Never the less during the spring this is THE spot in the Smokies to find wildflowers. Probably one of the easiest trails you can do, in the spring, that will lead to 15-20 different types of wildflowers and orchids.