The most challenging maps for you.

As I understand it, this topic was previously used, in the absence of a more suitable one, to discuss any custom maps, not necessarily those that are difficult to complete. This includes the aforementioned French map, which can only be considered challenging with some stretching of the imagination. I suggest trying Limes Inferior; it's 200% more challenging. Compared to it, even Xiedu seems like a walk in the park.