Rainbow Falls, known in Maori as Waianiwaniwa, drops 27 metres over a basalt ledge into a deep pool on the Kerikeri River. The falls are reached by a walking track that begins at the Kerikeri Basin, following the river upstream through regenerating bush for about five kilometres. The track is well-maintained and can be walked in either direction; most people do it as an out-and-back from the basin, though a loop via the road is also possible.
The river itself is worth pausing for along the way — it runs clear and cold over dark volcanic rock, and several points along the track are good for swimming in summer. The sound of the falls carries well before you reach them, and the viewpoint at the bottom gives the best perspective on the full drop.
The track passes through the heart of what was once a significant agricultural and mission landscape. Orchards and cleared land have given way to recovering bush in many places, and native birds — including tui and kereru — are common along the water.