Pitch camp in the middle of Sydney Harbour

Tom Adair visits Cockatoo Island as it opens up to the public

For several years it lay abandoned, a ghostly presence in the heart of Sydney Harbour, accessible only to those determined to reach it by boat. Now Cockatoo Island, has become a waterfront campsite in the middle of a city on one of the world's most beautiful harbours.

Captain Thunderbolt, the bush ranger, made his escape from the island's confines in 1863, swimming to freedom through the swift currents of the Parramatta River. Enid Blyton, had she known of its existence, would surely have sent the Famous Five to Cockatoo Island – it's a name her whimsy might well have conjured up.

Indeed, Blyton's young conspirators are in situ, swarms of them, zig-zagging between the ranks of tents. They have come to sleep beneath the stars, along with their families, who are already tossing sausages on the barbie, enjoying the latest getaway craze: the Cockatoo Island camping experience. I have joined them, the only non-Aussie on the block, enjoying my pre-erected Oztent RV-3, big enough to stand up in, complete with mattress, chairs and lantern. Enjoying, too, my ready-packed barbie.

"Yeah, the Sydneysiders are here to beat the grind," says Brendan from Greenwich. "Escaping the city without the trouble of having to leave it." "That's my house over there," he says, pointing due north to a red-tiled roof while he marshals a sizzle of onions and steak. He yells for his kids to come and get it. "Feed 'em up and they'll conk out later," he adds. He hopes.

Cockatoo Island is heritage listed, a world first. Outside my tent, I can see the arch of the Harbour Bridge, while behind me loom silhouettes of an old water tower and, beyond it, the rusting hulks of shipyard cranes providing their clue to the island's past. Cockatoo – the largest of seven islands in the harbour, three miles from Sydney Harbour Bridge (as the cockatoo flies) – once boasted trees and fauna in wild abundance. It was a convict prison for much of the 19th century, then a granary, a workhouse, a girls' reformatory and a 20th-century shipyard. When, in 1992, the shipyard shut, the weeds took over.

I ponder these facts as I share a few glasses of cabernet sauvignon, bought at the Muster Station Café beside the jetty, toasting my neighbours Brad and Katie from Drummoyne, another suburb just down river.

"All you need's a full-up belly, a beer, a glass or two of plonk and the island's your oyster," Brad declares. He reckons turning Cockatoo Island into a campground with a café, an ATM, toilets and washroom was a masterstroke. "Sydney should use its islands more."

The Sydney Harbour Federation Trust was set up seven years ago with exactly that in mind. It plans a Cockatoo Island comedy festival later in the year. Meanwhile, another government agency, Sydney Harbour National Park, is planning events from indigenous dance, to be held on Clark Island in October. to food and wine days on Fort Denison and a music extravaganza set on Goat Island.

At 2am, I am awakened by a thunderclap. Stepping outside, I focus on the starry spread of the heavens and try to picture this place on the night the first British ships sailed in from the ocean back in 1788 with only the sounds of nature to greet them. The modern silence is less enduring. First, a motorboat passes. Then a barge. I go to my tent but cannot sleep. At 6am, with my headset on, I step out and take the audio tour before camp awakes.

It's an engrossing two-hour stroll around the old boat slips, over the plateau and through the jail, built by the convicts who shared its privations. I pass two Federation cottages, now holiday rentals. The soundtrack relays tales of industrial unrest, of wartime boats limping in for repair, of a payroll hold-up. The path is rugged, the views superb.

Queuing for breakfast in the crowded café I run into Brendan. "Best weekend I've had in years," he says. "The kids are still asleep! He grabs a bacon and egg bap and the two of us munch our way back to camp enjoying the views of Sydney Harbour from Cockatoo Island's unique perspective: a timeless view at a knock-down price.

Compact facts

How to get there The Woolwich service on Sydney Ferries (00 61 2 9207 3170; sydneyferries.info) leaves Circular Quay and stops at Cockatoo Island several times a day, costing A$5.20 (£2.50) each way. Cockatoo Island (00 61 2 8898 9774; cockatooisland. gov.au) offers pre-erected tents from A$75 a night. The Federation Cottages sleep 10 and can be rented from A$300 per night. Ninety-minute guided tours of the island cost A$18. The self-guided audio tour costs A$5.

Further Information

Tourism Australia (australia.com).