Possible Underground Bunkers

This is the second UGB entrance. Not a huge installation, hasn't gotten too much work done on it in the past years. Possible 2 UGBs were built between 2010 and 2013. I'm guessing it's a military site as there seems to be a visible security perimeter, not super tight though. I don't think it's a mine or civilian industrial zone since there's not a lot of typical trailing and assorted industrial buildings that go with a mine or chemical plant.