A Google Earth Mystery: Kim Jong Il’s Big Dig

Yesterday, while MiG-spotting over  North Korea at an altitude of  about 20 miles, the highest altitude at which it’s easy to spot airfields, I saw something that caught my eye and went down for a closer look.  I’ve overflown that area multiple times previously and ever noticed it. 

At first glance, it looks like a runway going through a mountain.  And that was my first guess.  (Click images for full size and coordinates.)

Move in closer, and you can see the north entrance, with much construction activity.  The waste rock from the tunnel is being scooped out into some kind of long ramp on each side.  The ramp is obviously a part of the project; otherwise, it would be cheaper to just dump it in a big pile.  Clearly, something is supposed to travel, drive, roll, flow, or fly along this linear axis from one end of the ramp to the other (it’s anyone’s guess what else will be under that mountain).

The tunnel appears to have two levels.

Here’s the south entrance.  Plenty of construction work there, too.

My first suspicion was that this was one of the underground runways that are  part of rumor and lore among  U.S. soldiers in South Korea.  Admittedly, some details make this theory an  imperfect fit.  The tunnel entrance is just over 100 feet wide.  By contrast, most runways used by fighter jets are  about 160 feet wide.  Although the “runway” measures just over 6,000 feet long, it may be expanding to the north.  It would have to.  Most fighter runways are over 8,000 feet long; bombers and heavy transports need 10,000-foot runways.  That said, if the runway grows longer,  the “underground aircraft carrier” theory still seems more plausible than anything else I can think of.   

What else could this be?  There’s no way  it’s a railroad or highway tunnel.  It’s much too wide and long, there’s little traffic going that way, and it wouldn’t connect to any existing road or rail networks.

My next guess was that this was some kind of grandiose water project, but that doesn’t make sense, either.  The tunnel would be diverting the flow of a river away from a reservoir and an agricultural area to a place directly upsteam from the city of Wonsan.  One would also think there are easier ways to build a hydroelectric plant.

Interestingly, I didn’t find other users’ placemarks here to help me identify this thing.  Maybe NKEconWatch can help us.  Anyone know what this is?