The Sterling Hill Mine that is. I think most everybody who grew up in the northern part of NJ in the past 20 years of so has been on a school field trip to this place and will recognize it.
This is awesome. I lived near there in Sparta for years but never checked it out. This video makes me want to get into more freeride/exploring type stuff. Reminds me of my skateboarding days when we’d just go out with a creative eye looking for random lines in interesting spots...