Fen Kierden is a swamp located in Northern Anaxas. It is known to be inhabited by piikii, small sentient mimics who live in the thick trees and water.
The swamp is considered impassable - too deep to wade, too muddy to boat and too tangled to navigate through except by the most intrepid of explorers. There are also dangerous plants and nettles that can be deadly to intruders. Most people avoid it, as there is nothing of value to discover.