If you are interested in seeing anything away from the magnificent coast, you might like to check out the Blue Tier which is inland from St Helens.
We used to camp up there years ago on the marsupial lawn, before it was formalized with toilet and official parking area. There's a good range of walks there from short and wheelchair accessible to several hours, in a wide range of vegetation. Have enjoyed all the 2-3 hour walks.
It's a former tin mining area from late 1800s to early 1900s (I think) but the rainforest is reclaiming it. Great coastal views, flora and fauna, also mining relics if that's your thing. Sadly there's clear-felling going on up there, but I believe it's still well worth a visit.
NOT a good road from Lottah to Poimena (the start of the walks) last time we were there, but the logging may even have improved that?
Someone else will probably have more recent info on that.
More info on walks:
http://www.bluetier.org/tourism.htm