About 35 years ago, my Dad and I visited an old mining-related tunnel on the Etowah River (probably in Dawson County). The tunnel itself was not part of a mine, but two different mining companies worked on the project to divert the river through a ridge, so as to mine the river bed for gold.
The "old timers" told them they would not find enough gold in the river bed to pay for the costs - and ultimately they were right. The first mining company started on the upstream side of the ridge, went halfway then went bankrupt. The second company came from the opposite end and met perfectly (horizontally), but there is a 30 inch drop "midway", as the second company's "half" didn't match vertically. That is the source of the "language" at about 2 minutes or so in the video. It is hard to imagine a "first timer" going over that drop without some sort of exclamation.
We were satisfied with visiting the entrance and panning gold from some nearby creeks.
Oh, did I mention it was in January? Riding in 40-degree rain, in an open-top Jeep, was not my idea of fun. We had gone there with a Dawsonville resident and his son (15 year-old with a learner's permit). My Dad and the other guy were in my Dad's truck and as I was the youngest adult in the group (at 21), I was "selected" to ride with the 15 year-old per Georgia law (regarding learner's permits). It wasn't raining on the trip to the tunnel, but it was on the way back. I enjoyed visiting the tunnel, but that ride in 40-degree rain was one of the reasons I hate cold weather. Even with a poncho, it was not fun.