New South Wales has some lush and stunning national parks just about one hour from Sydney. I have visited the Colo Valley & went around the Blue Mountains national park - so called because the mist from the eucalyptus trees creates a typical blue-ish tint when seen from a distance. 
There are some pretty and quaint little towns such as Blackheath, filled with nice cafes & victorian houses. The drive sometimes can be pretty hazardous when off the roads, but it surely looks great. 

While mountain biking trekking I saw lots of spiders, a giant lizard and some kangaroos. I have also seen a beautiful river with sand banks in the Colo Valley. You can also do canyoning - which means going through the bottom of a canyon walking & swimming with the occasional jump into a dark pool.. It’s like an extreme bush walk, wet & cold but a lot of fun. I had no idea about the jumps and as I have a fear of deep waters I was freaking out but then did it anyway. It felt great :)