In the south eastern section of Azeno resides the region's most expansive marsh. Hubin's waters are a bit deeper than most marshes, due to constant water runoff on Mount Kenton, but not by much. Due to the deeper waters, Pokemon that would normally live in deep ponds or small lakes also live in the waters of Hubin.
Due to the muddy nature of the marshlands, this area of Azeno is difficult to travel through for most people. Trainers and wanderers constantly get stuck in the mud and deep waters of Hubin, so make sure to have a buddy system, whether it be with another person or a Pokemon. If you go alone, you might find yourself stranded in the marshland for quite sometime. Maybe some wild Pokemon could help you out.