It passes through the flatlands of the Malltraeth Marshes, where the river course was altered in 1824, creating a canal-like straight stretch. This part of the river and the surrounding marshes, part of which is a RSPB reserve, are frequented by a variety of wetland birds which in their turn are preyed on by falcons, hawks and harriers. A cycle trail follows the straightened course of the river as it flows through the marshes.
The river meanders through the flatlands of Malltraeth Marshes, where its course was altered in 1824 to create a canal-like stretch. This part of the river and the adjacent marshes, some of which are an RSPB reserve, attract numerous wetland birds that are hunted by falcons, hawks, and harriers. A cycle route follows the straightened path of the river as it winds through the marshes.