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 flows through the flatlands of Malltraeth Marshes, where its course was changed in 1824 to form a canal-like section. This area, including parts that are an RSPB reserve, is frequented by wetland birds that are preyed upon by falcons, hawks, and harriers. A cycle path follows the straightened river as it passes through the marshes.