The Blue Mountains National Park has many interesting things to do.
bushwalking
This is a very popular pastime in the Blue Mountains and there are a number of well-maintained trails that will offer you the opportunity to go down into the valley floor, viewing the changing vegetation as you descend. Lyre birds can be found in the undergrowth in the valley. (http://en.wikipedia.org/w...) They imitate the sounds of other birds, so you will probably need to keep your eyes open for them but they are quite a find for any bushwalker to come across. With many things to do, and many places to explore, why wouldn't you try it some time.
the zig-zag railway
At Lithgow, you will come across the famous Zig-Zag Railway. This train is a switchback form and was built in the 19th century as a tourist attraction, which it still remains today. At the time it was built, it was a major engineering feat.
sightseeing
There are a number of amazing sites to see just from the main highway and major roads. The Three Sisters is one famous site that every visitor to the Blue Mountains must stop and see. There are fabulous views from many vantage points and it is evident on a clear day why the Mountains received their name of "Blue", as the Eucalyptus shimmer in the distance, creating a hazy blue as far as the eye can see.