The cave faces SSW so it never actually gets the sun on it making it great for summer and winter alike. The cave is so large that it never gets wet in the rain but it does seep occasionally. While there is one "crumbly" section of rock the majority of the crag is some of the best quality sandstone in Sydney. There are lovely sandy landings under every problem but beware of the broken glass - the sand has been completely raked twice by the developers but local hooligans ensure it returns every time!

© (StuartE)

Access issues inherited from New South Wales and ACT

If you have benefited from climbing infrastructure in NSW, please consider making a donation towards maintenance costs. The Sydney Rockclimbing Club Rebolting Fund finances the replacement of old bolts on existing climbs and the maintenance of other hardware such as fixed ropes and anchors. The SRC purchases hardware, such as bolts and glue, and distributes them to volunteer rebolters across the state of New South Wales. For more information, including donation details, visit


Turn into Starkey St, Killarney Heights, off Warringah Rd and follow it for about a km then turn right into Connemara Rd. At the end turn right again into Killarney Dr, follow it for 100m and park on the grass on the left at the top of the Mosman Rowing Club steps. Follow these steps down for about 50m to the Flat Rock walking track and turn right along the track. After about 50m you'll see the headwall of a big cave up on your right and a faint track heading up the hill to it. This is it.

There are more direct paths that can be taken from the parking but with a crashpad they are pretty dangerous so the above approach is suggested.

© (StuartE)

Ethic inherited from North Shore

Respecting the enviroment and keeping crags clean will maintain a healthy and important relationship between the climbing community, local councils and National Parks. Carry out what you take in and enjoy what the North Shore has to offer.

If you come across an area that is being developed or you think could be under development, please show all due respect to the developers and do not climb the projects listed on


View historical timeline

Crumbly was first developed as a climbing crag by Peter Martin et al but they overlooked the big horizontal roof starts to all the routes opting for cheater stones and jump starts. It was so named because of a large crumbly section on the right where there was no climbing possible. Then Mike and Dave Kellermann independently discovered the crag on one of their regular boat trips up middle harbour and with the help of Tim O'Neill they realised the potential it held for great boulder problems. There are about 10 problems now ranging from V5 to V13. All the problems are steep and the best are actually horizontal - Chaos and Disorder V11? and Anorexic V5 are arguably the best problems for their style and grade in Sydney!

© (StuartE)

Some content has been provided under license from: © Australian Climbing Association Queensland (Creative Commons, Attribution, Share-Alike 2.5 AU)


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Grade Route

Start on two underclings at the far left side. Make a big move and head up and slightly left to finish. Don't dab the tree! Not great.

FA: D.Kellerman, 2000

Start as for Nasty but continue up passed its finishing holds and traverse high and right to end up on the finish holds of genesis.

mattias braach-maksvytis

FA: Tom Farrell

Low traverse, starting at Nasty and following jugs right to finish on Sushi Train's starting jug

Start on the big flake jug and make a very tough move up using the tiny crimp. A heel thrown onto the rail of 'Sushi Train' appears to help.

FA: D.Kellerman, 2000

Start 'Abacus' finish 'Genesis'.

FA: Chris Webb Parsons, 2008

"9 moves all up. Hard to grade." Mushi Brain finishing up Genesis

FA: Chris Webb Parsons, 2007

Start on the big undercling with your feet on the back wall and blast straight up, finishing matched on the huge jug left of the spike. Crafty toe-hooks are the key.

Stephen Rawls

FA: S.Langris/T.O'Neill, 2000

Start as for Nasty and make big moves out rightwards, finishing up 'Sushi Train'. Pumpy.

FA: T O'Neill, 2000

A.k.a. Phlegm starting at Sushi Train.

After the crux of Sushi Train bust out right to finish up Abacus.

Link 'Mushi Brain' into the last two moves of 'Abacus'

FA: J.Scarborough, 2000

Start on the undercling just right of Sushi Train's start and power up using the obvious poor pinch.

Travis B

Sam Healy

FA: T.O'Neill, 2000

Standing Start

FA: T.O'Neill, 2000

Extension to 'Abacus'. Need some spotters and mats for this one, its high and dynamic moves above your spotters heads.

FA: Chris Webb Parsons, 2008

Links 'Mushi Brain' into start of 'Abacus'.

FA: Chris Webb Parsons, 2007

'Sugoi' into 'Logical Progression'.

Or start 'Mushi Brain' into 'Abacus' finishing high.

FA: Chris Webb Parsons, 2008

Do the first move of Abacus, then traverse backwards through Mushi Brain to finish up Nasty. No traversing straight into the Sushi Train start holds.


FA: Chris Webb Parsons, 2010

Life Changes but starting as for Sushi Train. LC originally started as for Abacus.

Start of the underclings and make some bizarre contortions (including doing a full 180 degree spin) through the roof. Probably one of the coolest and most unique problems in Sydney.

Travis B


FA: D.Kellerman, 2000

Start on the big undercling in front of 'Mull up'. Launch out through the roof and link into the last few moves of 'Anorexic'. Double toe-hooks are the trick for the funky 'drop down' move. (The main hold, the pinch/crimp has been broken off making the problem significantly harder)

Chris Beers

Liting Xu

FA: M.Kellerman, 2000

Link 'Black Magic' into the finish of 'Exodus'.

Anorexic finishing on the start hold of Black Magic

The warm up. And one of the best problems of this grade & style. Start at the back wall and pull straight out the roof, passing the big hole, make a long throw and finish MATCHED on the huge jug. Hold that swing!

Jordan Maxwell

FA: T.O'Neill, 2000

After reaching the finishing jug, keep going a few moves further and finish on an even higher jug, up and left of the spike on 'Exodus'. Scary!

Link the Traverse into 'Anorexic' and finish as for the 'Anorexic' extension. V7' ish but probably deserves a sport grade.

Start slighty right of 'Anorexic'. Move through the roof with your hands staying clear of the holds on 'Anorexic' although your feet may stray over. Keep going past the old bolt and slap up the sloping prow to finish on the the big spike. Unrepeated since a hold broke?

FA: T.O'Neill, 2000

Link 'Anorexic' into the finish of 'Exodus'.

Start a few metres right (just before the rock gets bad) and traverse left into the start of 'Anorexic'.

FA: T.O'neill, 2000

Low start on crimp rail straight up to finish matched on slopey rail. Cleaned up nicely.

FA: marc landers, 27 Jan 2015

Start at Genicus and go up through crimp rail to slopey rail. Traverse rightwards till the holds end then make a big move out to jug in the roof.

FA: Phil Neville, 27 Jan 2015

Sit start on an incut RH crimp and LH slopey crimp. Go up to the break and traverse right to the big bucket jug. Head straight out the roof to the last jug via some big spans.

Starts as a sit/crouch start on the chalk at the far right of the crumbly cave and then up the “v3” and into the roof to finish on the last big jug (same finish as leviticus)

FA: Chris Webb Parsons

Sit start on undercling. Finish matched on sloper to right.

A sit start problem near the bottom of the dicey access gully

FA: Kyle Dunsire, 2000

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