Ariki Falls is roughly a 2 hours' drive away from Greymouth. The road surface is always sealed.

From Greymouth travel north on the SH-6, then turn onto SH-69, then finally onto SH-6 and follow it for the next 35 km until you reach a car park associated with Buller Gorge Swingbridge Adventure and Heritage Park. There are toilets and quite a big picnic area.

Go to the office and buy a ticket for Swingbridge and walks (5$ per person in 2013) to get access to the walking tracks. A walking 1-hour return Ariki Falls Walk leads to the waterfalls top. You'll need to cross the swing bridge during the trip to the waterfall. The track is quite an easy one but can be slippery after a rain. 

There are two more small waterfalls which you can see during your walk - the first one you'll see immediately past the bridge, on the opposite river's shore. The second one you'll see from the Ariki Falls lookout.