If you are looking for something fun and adventurous than the Knapsack Stairs is the way to go! (This is not something I would recommend to those who have injuries or are unable to cope with walking up and down stairs) In saying that if you are wanting a good workout or bushwalk this is one of a kind! Knapsack Stairs is located in the lower part of the Blue Mountains and is a short drive from the city (Sydney)
Once you reach the top after tackling the stairs you are able to see the beautiful views of the city (Sydney), Relax and enjoy on either the park benches or sit comfortably on a rock. Either way the views are breathtaking and well worth it.
Make sure you take lots of water or even a small picnic lunch to enjoy the tranquillity and wildlife around you.