I really did my best when I wrote the section in Pete's guide to deter anyone from bothering to try find it. Pete wanted it in there for the sake of completeness only. Don't bother. The only good line has a death fall. DEATH.
However, the Washaway slabs, upper and lower tiers, are spectacular, and offer some of the *best* vertical and under-vertical bouldering in Sydney. The style at the lower seam is reminiscent of the Peak District.
The lower tier is an 8 metre thick monolithic seam (read: no horizontal breaks) of sandstone. Counting the slabs and the boulders in the forest area (along the track towards Castle Rock beach), there are around 120 developed problems ranging from V0 to V8. I've drawn up a topo that I happily give out photocopies of, but I've never made it publicly available due to the fact that climbing is technically banned in the Sydney Harbour National Park.
To get to the slabs, I park at the lookout at the Eastern terminus of Cutler Rd and walk 20 metres down the track until it intersects with the Manly Scenic Walk. Then, without joining the MSW track, walk straight another 20 metres until you get to a concrete bunker. Get below the bunker to the left and follow the overgrown gully 50 metres straight down until a small jump-down seam of rock, then another 20 metres to a bigger seam. This seam is the upper tier and has good bits in either direction. Continue down 50 metres further until you hit the biggest 5-8m seam at a big balcony of rock and you are at the lower tier. Again, problems go left and right from here and include some of the best lines in Sydney. Once upon a time we made nice tracks, but they get totally reclaimed by the bush each summer.
At the arete where you pop out there is a five star problem called "The Balcony" V2. it involves a huge dyno move off a sidepull flake to a pocket. Here is a Picture of Phil Schaal pulling through the dyno (scroll down to the 4th pic): http://phillipschaal.blogspot.com/2010/09/oz12.html
By the way, I should mention - most of the better lines there are for the very seasoned boulderer only#. For example, one of the V1 highball problems - Old Man and the Sea - I wouldn't send anyone up who climbs less than V8. I would put a similar constraint on any of the harder slab problems (and I'm only talking about V3 and up). There is a lot of no fall territory.
This is not "The Balkans II".
# I'm going to define "seasoned boulderer" as someone having ~10 years climbing under their belt, being *competent* on V8, and having experience with headpointing.
Yep, remember that it is national park and that bouldering activities can have a heavy impact on vegetation, and the heathland vegetation in that area is some of Sydney's most accessible (and most accessed too due to the Spit to Manly walkway).
Lambertia formosa Mountain Devil - on the track to Grotto Point.
I love that area, and have been a 42 year local (hiya Dave K), so please consider minimal impact activities. There is some OK deep water soloing (when the tide is up) between Castle Rock Beach and Grotto Point - just follow the shoreline from Castle Rock.
The area also used to be heavily used by aborigines, and there is still some evidence of habitation in the area. I was there last October and 'rediscovered' (I remember it from when I was very young) the original aboriginal track used to access Washaway Beach - there was a very distinct rock shelter on the track with midden shells, fireplace and axe sharpening grooves in the rock (not to mention some spectacular rock art of animals closer to the carpark).