Starting at Allen Park, on the corner of Blaxland Road and Terrace Road.  The track starts at the south-west corner of the park (which is really just a soggy square of grass).

Heading down the track about 100m, then turn left near the bottom onto the Great North Walk.

There's some interesting rock formations along the trail, with a natural tunnel in one spot, and beautiful views across the Lane Cove River.

The trail get's runoff from the hills above, but I think it would still be doable in all weather.  Footing is a little difficult here and there.

When you're coming close to Fiddens Wharf Road, there's a few bridges over creeks, then turn left for some steps up to the oval, then some more steps up to the road.