I was interested in map that come with Patch 5.2, called GoldRushBG. in the first I thought it is not yet finished, or they just put the files with names and no any informations. I was curious, and I have start to dig those map files. In the end, I realize it is the map that is not yet finished and in an early stage of development. But when we look it, from Air we can see that they are similar, since both half's are same.
Could this be second Battleground that Blizzard is working on. One more interesting part is that map is small when I look at it.