We have been to Dwellingup on a number of occasions, the park is nestled in the forest and the lightning at night is something out of the ordinary, the lights are done so that they shine up into the trees giving it a magical feeling.
You are only about 1/2 hour from Pinjarra and you also have Lane Pool reserve just up the road.
It is definitely worth taking the time to have a look as there is plenty to see or just relax in the natural surroundings.