Looks to me like you have one of their new ballistic missile bases. They hide the bugger in the mountain and then wheel it out. This one doesnt look completed however. I'll add there looks like to little security, although there are guard posts at the road intersections. That can be attributed to the thing not being near completed yet and anyway the country is an armed camp to begin with.

I can think of no other reason to build those long platforms. OK, a little research reveals the Anbyon chemical warfare facility is located south of Wonson and its located in a mountain. That looks like what you have here. I also found some referance to a new missile base being built around Wonson. All the living facilities around the area would also suggest "under construction". Go directly S/SE of Wonson at the beginning of the mountains. There appears some type of launch facility there. or is that for SAMs?

Nice grab.