The Department of Conservation (DOC) that look after the National Parks in NZ are brilliant. I drove all over NZ in a campervan about twelve years ago - as many do - literally every second vehicle you see is a campervan - and everything is really well signposted. You pull off the road into a layby, and there will be a wooden sign saying "Waterfall - 30 min walk" and then you follow a well kept path for 30 min and then you find a waterfall. Simple! And there are unstaffed DOC campsites in very beautiful places with very basic facilities (tap, compost loo). You just stay the night and then drop an envolope of cash into a box. And the huts in the middle of nowhere that take days to hike to, somehow they keep them maintained too.