Sydney has better beaches than any other city in the world, and you’d be crazy to go there and not get your share. Trouble is, they get pretty crowded. So, how would you like to find one that’s usually empty at the height of summer, a 200yd stretch of bush-backed desert-island perfection you can have all to yourself?

Store Beach isn’t in the guidebooks, and many locals haven’t even heard of it, let alone been there. There’s a reason for that. You can’t reach it by land. You’ve got to paddle. Which sounds like a hassle, until you realise that getting there is actually easy, and almost as rare a pleasure as arriving. You could do the whole round trip from the centre of town in a couple of hours, but there’s no hurry. Let’s make a day of it.

Start bright and early at Circular Quay. (Naturally, it’s square-shaped. This is Australia.) Hop on the stately green-and-yellow ferry to Manly (£5.70 return): a little tacky, a lot trendy, the suburb now pulls in surfers in their neoprene-clad droves.

The half-hour ride just isn’t long enough for a trip this pretty. You nudge almost to the foot of the girdery gorgeousness of the Harbour Bridge, then swing right to within a wombat throw of the Opera House. Then it’s east, and the world’s biggest and most beautiful natural harbour opens out in front of you.

You pass Russell Crowe’s Woolloomooloo pad, the ominous grey destroyers of Potts Point naval base, Shark Island and the millionaires’ mansions of Balmoral and Vaucluse. This is, believe it or not, a commuter route. It sure beats the M25.

The ferry docks on the harbour shore of Manly. The town is built across a headland, so it has another beach, facing the Pacific Ocean - which is where we’re going for breakfast. It’s a five-minute stroll through the kiss-me-quick tat of the Corso to the thundering breakers of Manly beach.

Absolutely the best spot for brekkie is the chic Ocean Beach House, a few yards to your left on North Steyne. Prime location, bang over the sand, with a grandstand view of the massed ranks of surfers ripping the waves 50yd out; laid-back modern decor and an Ibiza chillout soundtrack; and great breakfasts. Choose between muesli and a smoothie (£7) or a free-range-egg fry-up with a morning kir royale (£11.50). We know which we’re having.

Back down Wentworth Street - stopping at the corner of Darley Road to pick up a picnic of fresh ham, game pâté, goat’s cheese, olives and Canberra rosé from the Four Olives deli - and, just yards from the ferry stop, you’ll find the matey surfies of Manly Boat & Kayak Centre.

A double kayak costs £24 for three hours, and there’s a dry bag for the nosh. Don’t worry, it’s the laziest of half-hour paddles: you can see out through the headlands to the wild swells of the Pacific, but here the water’s calm and easy. Mostly. Just don’t stray too close to the ferries - they make a hell of a wash.

Round the rocks of Little Manly Point and you’ll see Store Beach for the first time, half a mile off: a strip of creamy sand, backed by hills covered in impenetrable bush. No roads come here. No paths, either. Yachties picnic offshore at weekends, but mostly it’s deserted, apart from the local colony of penguins.

Paddle ashore, hop out, kick back. It’s pristine: the only sound is the squeak of the powdery sand under your feet, the only sign of human presence a small notice proclaiming the beach to be part of Sydney Harbour National Park. Paddle, swim in the clear water, work on your tan, then sit in the shade of a gumtree and tuck into that picnic, gazing across the turquoise wavelets at the skyscrapers in the distance.

And ponder. Most people trek up to Queensland or the Whitsunday Islands for this sort of splendid isolation, but here you are within a city of 4m people, utterly alone in one of the most beautiful spots imaginable, an urban Robinson Crusoe. Only one thing need concern you now. Where did you pack the corkscrew?

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