I'll give you a hint... if you wanted to go to the highest point within 20 miles of the lowest point in North America, you'd drive right past these kilns. At least that's how I stumbled across them...
Inyo County, CA near Death Valley. Website: https://www.nps.gov/deva/learn/historyculture/charcoalkilns.htm
A very interesting place... ( Death Valley and surrounding area ). Prior to that trip there, I had never had any idea of how charcoal was made... It still didn't really make sense to me why they would build the kilns in that particular location, it seemed extremely remote, didn't seem like there were that many trees around to use to make into charcoal... ( but then I'm born and raised in Michigan, where trees are everywhere ).
Of course on that same trip, in like 5 days I drove from Las Vegas, to Death Valley, down to Joshua Tree... , across miles and miles of old Route 66, through places like Oatman and Kingman... kind of amazing how much of the old road is still there... to the Grand Canyon, then north to Bryce Canyon, over to Zion NP, and on back into Las Vegas ( coming into that city at night time on a lonely desert Hwy is quite a site to see ). So, the charcoal kilns were just one of many interesting sites I saw on that 1400 mile trip around the Las Vegas strip... Much of it was flying by at 70 and sometimes 80 MPH though. I probably wouldn't be very well suited for such a long and fast paced sight seeing trip these days, but I'm extremely glad I got to see that area when I did. Very cool stuff around the whole area out there.