From the deck, you look out across untouched white sand, and the sun glistening on the surf. Below, in the garden, banana trees flourish. Is this Australia, perhaps, or California? Wrong. Try closer to home. Try Cornwall... Report by Anna Pavord. Photogra
Driving to Cornwall, you have the curious feeling that the edge of the map is looming up in front of you rather fast. At any moment you expect to hurtle off the narrow pointed toe of the British Isles, next stop America. The chubbiness of Devon gives way to a tougher, gaunter landscape. Instead of trees, there are forests of tall, white windmills, enigmatically spinning light and heat and microwaved suppers out of the damp Cornish air.

On the very edge of the edge, hanging on to the brink of the cliff on Cornwall's north coast is Hawke's Point House, home of Ann Kelley and her husband, Robert Marshall. To find it, you have to abandon your car and take to the coastal footpath which leads over the railway tracks of the St Ives to St Erth railway and plunges down into the lush undergrowth of the headland behind Carbis Bay.

If you jumped from the path, you would land astride the wood-shingled roof of the house, which is tucked under you on a narrow ledge, the only bit of flat ground left before the land tumbles precipitously down to the sea. Taking the easier option of the path to the front door, you squeeze down narrow steps between sheaves of montbretia and tumbling curtains of ivy.

When the front door opens, you step over the threshold into a bath of distilled light. After the dark tunnel of the approach, you enter a room so bright, so white and so shiny, that you blink like a mole surfacing in Piccadilly. Big windows ahead of you look out on to the turquoise water of the bay. A sky blue sofa sits looking at the sea. Everything else is as bleached as driftwood.

The floorboards are the colour of sand and the mats are made of seagrass. White muslin blinds shade the glass roof of the room that Ann and her husband, a local doctor, added to one side of the sitting room, and white gloss paint covers the boarded ceilings and walls of the rooms. The light is extraordinary.

Although Ann had spent much of her life in St Ives, she did not know about Hawke's Point until she went house-hunting for her brother-in-law. He never had a chance. She saw the place, fell instantly in love - despite the brown-and-gold paisley wallpaper that covered most of the boarded walls - and telephoned her husband with an incoherent account of the view, the jungle garden, the cliff, the possibilities. Seventy thousand was the price. "Well, buy it then," he said. "So unexpected," says Ann reflectively. "He is usually such a careful man."

And was their surveyor so easily persuaded of the house's strange charms, you wonder. "We had two surveyors' reports, and they were both appalling," replies Ann candidly. "One said the place was probably full of mineshafts. The other that the house had no foundations." Every Eden has its snake. They bought the place anyway.

The idea then, six years ago, was that they should use Hawke's Point as a summer retreat. It was all of two miles from their existing home in St Ives, but at the end of one summer, "Robert just refused to leave. So we stayed." (Robert's adult daughter now lives in the St Ives house.)

The first winter at Hawke's Point nearly killed her, Ann says. The roof felt as though it was going to be ripped off by the northerlies and easterlies. There was no central heating and Mongolian draughts whistled through gaps round the windows and cracks in the weatherboarding. As the house was then too small for permanent occupation, Ann - a former stylist for fashion shoots - set to work.

Decks were the answer. The first one was slung out to one side of the sitting room to provide a little glass-roofed room leading on to a big sitting-out space. The guard rails are made from stainless steel yacht stanchions strung at intervals with the twisted wire that boatbuilders use for halyards.

The deck sails out over the garden, supported on huge wooden pillars thicker than telegraph poles. Banana palms and tree ferns tickle the joinery underneath. The land falls away vertiginously in a mass of bramble and thicket. "Yes, I did have vertigo when I first came here," says Ann, "but I quickly talked myself out of it."

The second deck is at a lower level and runs along the seaward side of the house, almost a whole storey lower than the level at which you come in. Most of the space is taken up by a new lean-to extension with glass roof and walls, but there is enough space left for a boarded balcony with guard rails that match those on the upper deck.

Inside the lean-to, which is used as a study and work room, bright blue canvas dodgers are stretched like blinds under the glass roof to provide areas of shade. The surrounds of the porthole windows in the shower room are painted an equally bright shade of blue. On the high bracketed shelves there are fish-shaped plates, floats and wooden boat lamps with parchment sails. Was their other house like this, you wonder, all sea shantyish and nautical kitsch?

"I blame my parents," she says. "My dad was in the Navy for 41 years. Then he had a coastguard station. I spent all my early life surrounded by ship's wheel clocks and things like that. Dad had a flagpole in the garden and used to run up the white ensign at every opportunity. I nearly bought a flagpole the other day. I stopped myself just in time..."

That was a pity. The huge, magnificent scroll-topped window, around which the turn-of-the-century cottage seems to have been built, could do with a flagpole underneath it. It would add the final touch to the illusion that, sitting on the deck here, you are about to slip your moorings and sail off on a long, long voyage across the turquoise bay. Inside the house at Hawke's Point, there's a very fine boat trying to get out