Spouting Horn is a classic quick stop: a lava tube at the waterline forces incoming waves through a narrow hole, sending spray into the air with a hollow hiss. It is most impressive when the swell is active, and slightly underwhelming when the sea is flat.
The viewpoint is paved and easy, with souvenir stalls nearby and the botanical garden visitor centre just up the road. Do not climb down onto the rocks; the ocean here is stronger than it looks.