The Plaatbos forest walks start near Storms River village and range from short loops to longer paths through indigenous forest. They are quieter than the river mouth boardwalk, and better if you want to hear birds and water rather than cameras and tour groups.
Expect forest shade, damp earth, yellowwood, stinkwood, and occasional openings where fynbos takes over. Check current access and permit arrangements locally, as SANParks has been tightening management of the forest entry points.