Hi sweetiepark.
I have been to both Ravensbourne and Crows Nest NPs last year. Both parks really only have one simple track system each but they are scenic and definitely worthwhile. I get the feeling they are often overlooked because they are out of the way, but I really like them.
The track in Ravensbourne has some loops through interesting rainforest and has some Aboriginal heritage. Apparently it was part of the path that lead over the range to the Bunya Mountains, and there are Aboriginal diggings through the rainforest. The track goes down to Buaraba creek which is lined by some massive blackbutt trees. When I was there I did some further exploration up and down the creek. I think the loop is approximately 8 - 10 km all up.
Check out this map ->
http://www.derm.qld.gov.au/parks/ravens ... np-map.pdfCrows Nest NP is lovely too and has an amazing swimming hole. Obviously not for swimming at this time of yearr though! I was there in December and the swimming hole was glorious! The single track goes on past the water hole to a look out over the valley. I think from the car park to the lookout and back is only about 5 km. But if you want a bigger challenge, I think the Daly's 'Take a walk in SEQ' book might have track notes for some off track exploration into the Valley of the Diamonds. Crows Nest NP has a lovely little camp site and the best thing about Crows Nest NP is all the rock wallabies, which are best seen sunning themselves along the creek in the morning sun!
Crows Nest map ->
http://www.derm.qld.gov.au/parks/crows- ... est-np.pdfSome pics below of Crows Nest and Ravensbourne for inspiration.
Cheers
Andrew

- Water hole at Crows Nest NP

- Valley of Diamonds from Koonin Lookout, Crows Nest NP

- Brush-tailed rock wallaby

- Blackbutt (Eucalyptus pilularis), Ravensbourne NP