Port Robinson Walkway is a nice coastal track connecting Gore Bay and Hurunui River Mouth near Cheviot, North Canterbury.
The entire walkway takes 3-4 hours one way. Alternatively you can park in one of the four car parks along the way and just walk a portion and not worry about transport arrangements. There is a section which is tidal near Gore Bay. Walkers will need to check for time of low tide to walk this section. Do check out the Cathedral, which is a very remarkable clay cliff in the area. Click on the image to the left for Port Robinson Coastal Walk in a larger map.