The synchronous fireflies of the Smoky Mountains are a natural phenomenon that only happen once a year. Here's how to see them in Tennessee.
![Best Things To Do In Smoky Mountains National Park [Itinerary Included]](https://i.pinimg.com/originals/a3/a1/9e/a3a19eddfbddb5af6e38b25d799d024e.jpg)
