There are several unnamed creeks here in the newly created Berowra Valley National Park at Westleigh: http://www.environment.nsw.gov.au/NationalParks/parkHome.aspx?id=N1187
I took a renewed interest in exploring these little known and unnamed creeks recently, when one of them featured in the international news. A local boy with a medical problem took off with a small amount of food, and disappeared for nine weeks. His parents and the police feared the worst, but he was discovered in a little-known creek bed, alive, though only just, covered in leeches and with only half his previous body weight. A couple of senior citizen bushwalkers, keen off-track creek explorers like me, had stumbled upon him by chance. He was helicoptered out to Ruddock Park and taken to Hornsby Hospital. Rescuers said he'd have died within a day or two. 
Elouera Creek was a joy to behold. Waterfalls, caves, fabulously colourful angophora trees. Even things to eat, methinks, at least for the fit and functional survivalist: water dragons, fish, colonies of ants even.......
I've hatched the idea of exploring all of Westleigh's creeks and putting them all together into a boy's own adventure walk for the bushwalking club later this year. I'll keep you posted.
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