The rubies underground, such as pearls, emit a charming beauty to Tennessee, the first thing to feel is that it is rare and simple. It is basically the same as the American countryside in our impression, very original ecology. The next day we came to Tennessee, we set off to visit the beautiful scenery. On the day of the play, we came to the place known as the largest and deepest underground waterfall in the United States and can be open to tourists. As soon as we heard this underground waterfall, we suddenly became interested. What will this underground waterfall look like when you see it on weekdays? After entering the cave, I have to feel that there is really no cave in it, it is an underground world! On both sides of the aisle are stalactites, stone slabs, stone pillars and other caves must-have "specialties", walking around, finally came to our most curious place - ruby waterfall! The waterfall spewed from the towering rocks on both sides, changing colors from time to time under the light: red, yellow, green, etc. Seeing this, I can't help but remind me of the magic world in the TV series I watched when I was a child. It was really interesting! I don't know where the source of this waterfall is, maybe it is an underground dark river? We can't tell. Warm reminder that the temperature in the underground cave is lower than on the ground. It is recommended to bring a thin coat.