The tough thing about exploring is that for every amazing thing you find, like a Jamul Kiln, sometimes you find things that are just there. They're not bad, they're not good, they're just there. Take for example the Cottonwood Kilns. They are part of California's gold rush history, and were constructed in 1873 to provide charcoal for the smelters at the nearby Cerro Gordo Mine.
Back in February, I was talking about a place off of Wildrose Road, the Eureka Mine, which you used to be able to explore (or so I was led to believe). (Article here). A couple weeks ago, after I passed through Trona, I stopped by, because I wanted to check it out as it was closed in February. I stopped by one entrance, and then another, and then another, and found the same thing you can see in all of the pictures: the mine entrances were blocked off. At this point, I stopped, and had a good think. Those metal bars blocking the mine entrances? Fairly permanent. And by fairly permanent, I mean, actually permanent. I'll admit that I didn't have time to talk to a NPS Ranger about this, since I was on my way to 20 Mule Team Canyon, but at this point, after visiting twice at two completely separate times in the year, I can only conclude the mine is closed for good at this point. It is, however, still a really cool spot to visit, and after all, the mine is probably closed to protect the public from Morlocks, and that's a good thing!