There is a lambach style map (which often even has lambach tentacles pop up) with a red background and infected looking theme over an outdoor rocky area. The map always leads to the upper right direction and has a pit in the middle of the first section, with a large red blob on the upper right side of it. Enemies spawn on top of that red blob and are unable to move, but can be killed. It seems like it is supposed to be an inaccessible area for characters and enemies, and I can confirm that the enemies on it are in fact higher off the ground (because thrown phantom blades go upwards). I have seen smaller enemies on it every time, but also saw a boss stuck against it one time.