Hold on now. I'm sure the tank has something to do with it. The tank is located in 4 maps: Badwater Basin, Double Cross(Nightfall), Granary and 2fort. Looking at the image closely, you can just barely make out various locations that look
similar that are located in those maps. Now, find their locations on the map. Only two are labeled: Badwater, and Teufort. Using the the terrain of the other two maps as guides, it's a good guess that they are located here:
View attachment 126585
With that, they can be linked like this:
View attachment 126586
If what Shepettan says is true and the locations of Meet the Medic and Meet the Pyro are shown in the pixelated map, then the third location has to be somewhere in the triangle.
Also... Does anyone remember this scene in Meet the Medic?
Let the speculations commence.