In a sunny patch I took them to the new arboretum - there were a million people there (I'm not sure why, because it's very new and none of the trees are grown). The boys saw this terraced arrangement and just took off for the distant horizon. The scale is quite deceptive but there are two boys in the landscape if you look closely.
We also did a two and half hour walk through a pine plantation just a few minutes drive from our house - I'd been past it a million times but never actually done the walk. The pines were pleasant and a very different landscape from the usual paddocks and gums. It would have been quite peaceful and serene for other people ... who weren't listening to the hundredth rendition of "Misty Mountain Road" from the Hobbit sung badly by two boys as the fog came down and the rain started. They also regularly jumped off the road and hid under branches from the Ringwraiths.
A fair bit of the walk was along the top of the ridge line - no trees and a bit scrappy. And definitely up in the fog and the clouds. But worth it - not a peep out of them for the rest of the day :)