This is something I found by accident, in the nothern province.
As the name suggest, it is a blue ground texture.
Things needed: Invincibility(up, down, up, down, left, right, left, right), and a helicopter.
To find it, you either can look at you're map on the PDA for the square that says "135"(in the bottom/middle right corner), or go to Yongbyon Station(also in the bottom/middle right corner)an follow the train tracks that go east and then go north(the one that turns left), follow that untill you reach the yellow/black gaurd thing, and go strait north, you'll come across a canyon where at the bottom, there should be a blue ground, oh, and you'll be in the Restricted Area.
I did it with the X-BOX(reguler) and I don't know if this will work on everything else.