I leave the rusted fencing behind me and return to cruise mode, following an easy right-hand curve beneath arching trees. To my left, the woodland gets higher and steeper and then suddenly the first set of cliffs known as, Seawalls, announce themselves.
A giant ramp of rock juts up towards the sky, joining a ragged vertical face that peaks at around 70 metres. I spot a couple of climbers, their bright vests and stretched limbs marking them out like strange crabs against the limestone.
I hop off my bike and balance on the kerb, waiting for a gap in the traffic, when there is movement in the air. I double take as what I can only assume to be a Peregrine Falcon, swoops lazily across the road and disappears behind the trees. ‘Tis the season I am soon to discover (see photos).
Across the road is a grassy bank and I trudge over it, losing sight of the road. Then the cliffs are all about me, magnificent and daunting.
I spy more climbers attached to the rock at impossible angles while others teeter about near the bottom. Towards the far end of the area is a gravel car park with a few cars and a mini-bus parked there. Ropes are strung up next to it, leading youngsters with mandarin-coloured helmets up and down the shorter part of the cliffs.
Back on the Portway, I find another enclave, labelled with the less adventurous title of Main Wall. However, this one appears much less tamed than the first. A Co-operative lorry and a line of cars are parked in a lay-by, all driverless. Behind them a mound of earth lies where a red barrier has long since been raised and left for dead.
I clamber over the earth and find myself in the remains of another car park. White lines painted on the tarmac get lost in fantastic carpets of orange moss while greater heaps of vegetation create corridors down which I wander.
There are odd remnants of human activity scattered about; a crash-landed radio controlled plane, a wildlife research project and a memorial of lanterns and flowers at the foot of the cliffs. I stop here a minute for some cool reflection and look up at the rock. It glares back at me unrelentingly, with a face even more extreme than the last in its concave shape.