The Ullen River (known by locals as the Dark River), originates from the farthest south of the Footprint Lakes(Twin Serpent Lakes). The River flows west past Riverside Province into the jungle, then turns decidedly south parallel to the Henge of Denravi, and ends at the marshes of Tangle Root. It is called the Dark River not just for the darkness of the passage through the cliffs but also for a perceived darkness that shrouds this river.