Rugged and exposed Turakina Beach (and the small beach settlement of Koitiata) is to the southeast of Whanganui, about 25 minutes drive down SH3 and Turakina Beach Road. There is a campground near the beach entrance.
The interesting feature of this beach for a first time visitor is the walk along the Turakina River mouth and nearby lagoons. They are both picturesque in their own right and laden with driftwood, piled up in places along the edge of the river. Apparently the lagoons, exposure of driftwood, and the river mouth can vary considerably over time, depending mainly on prevailing weather.
When we visited, it took about 30 minutes to walk all the way to the beach, unless you wanted to chance a crossing of the mouth which did not look enticing.