There are soo many places to explore in Springbrook National Park. Waterfalls and Hiking tracks are everywhere.
A good one for hiking is Purlingbrook Falls hiking trails. Be aware it is a lot of stairs, but once you get to the bottom it is beautiful to look up at the waterfall. It's like a scene out of Jurassic Park.
If you go hiking deeper into the bush down to the natural pools, just be on the look out for snakes on the trails. and there are plenty of snake like lizards, which I believe to be harmless, but try not to get too close just in case.
The Natural Bridge waterfall is nice, but if you are looking for a hike, you won't find it here. the walk from the car park to the waterfall is only a few hundred meters and only takes about 5 mins. if you get here early enough before the light, you can see glow worms in the cave ceiling.
Also be on the lookout for wallabies and kangaroos that hang out on the side of the narrow roads in the area. if they get spooked, they may jump in front of the car. so always drive cautiously.