Iron Age fort a powerful status symbol for outpost in south Cornwall

Here is the perfect beach for one of those beautiful autumnal days when the sky goes on forever in a vast arc of metallic blue and a chill breeze cleans up the air so that everything sparkles clear and bright, like it does at no other time of the year.

There is a good reason why this secret seaside fits the bill so well, and that is the small – or rather, large – matter of protection. Such autumnal days tend to be on the nippy side, so it is no good hoping to loll about enjoying an out-of-season picnic on some west-facing shoreline where the prevailing breeze will turn your bread rolls into brass monkeys…

What you need is somewhere south-facing accompanied – immediately to its west – by a vast headland acting as a wall of protection. Vault Beach is that place. And the mighty Dodman is the magnificent headland which shields it.

I do not exaggerate the shelter offered by Dodman Point – it is the highest point on Cornwall's south coast. As such, you can see it from far and wide. It almost acts as a kind of maritime gatepost to the far west. When I catch a glimpse of its dark mass from, say, Dartmoor's southern slopes, I feel that promise of romance that the land of the setting sun never ceases to inspire.

The Dodman, if you have never been there, is the bold fortress of a peninsula which divides the bays of St Austell and Veryan like some gigantic tooth ready and waiting to rip into the soft under-belly of any passing ship.

Tucked just east of it is long, lovely, sandy, little trampled, Vault Beach.

"Down-along, out-along"… That's the way the writer JRA Hockin described this stroll 80 years ago in his estimable Walking in Cornwall. He was talking about the "restful slopes, turfy and bracken-spread" that you will find beyond the little fishing cove of Gorran Haven.

I would give a very high sum to jump into a time-machine and belt back to the Cornwall that Hockin saw and enjoyed 80 years ago – it was, perhaps, a great deal more authentic, less developed and less an homogenised part of our modern globalised world than it is now.

But if there is one thing that is definitely better today it is the state of the footpaths. Hockin describes the "hair-raising" aspects of following a "barely discernible" path above Great Perhaver Beach – then he gives up following the coast altogether to head inland up to Gorran Church Town so that he can reach the Dodman headland…

We don't have to worry about any of this because this region's finest feature – i.e. the South West Coast Path – continues magnificently on past the Haven to round Pen-a-Maen, sometimes called Maenease Point.

It then traverses the steep wild coastal slopes to round Cadythew Rock – and now, and only now, can we see the great beach which is our destination – a beach so wondrous I'd put it in my favourite top five.

Vault or Bow Beach is a quarter-mile long stretch of sandy paradise – made even more perfect on chilly autumn day when there's a wind coming out of the north-west. You will see its icy fingers fanning the wavelets out along the flanks of the Dodman, but down on the sands you cannot detect their goose-pimple touch.

There is a slightly odd price to pay for all this protection – show me a pleasant remote beach which is shielded from the prevailing winds and I will show you (actually, I'd rather not) a person with no clothes on.

Vault Beach is a destination for nudists – as I found out last time I lay down alone on its comely, sandy, bosom and dropped off for 40 well-earned winks.

Something – some instinctive reaction that someone was watching me – caused me to stir. I opened a single eye and there, just a few feet from me, was a naked man who seemed to be examining my textile covered body with some interest.

"First person to do that in a long time," commented my wife when I returned home later that day. And she spoke the truth – so maybe I should have been vaguely pleased. But I wasn't. Despite the fact that I had nothing to fear – I was bigger and I reckon much fitter than the man in front of me (and believe me, I had visual evidence to prove this notion) – there is something disconcerting about being gazed at by someone with no clothes on.

So, 23 winks short of the 40 I'd been hoping for, I departed and went for a quick turn around The Dodman. The National Trust owns much of the headland, partly thanks to an anonymous donation back in 1919, but also because of funds raised by the organisation's Neptune campaign, inaugurated to save important coastal areas 45 years ago.

The place is rich in archaeological remains. There is a well-preserved Iron Aged "promontory" fort defined by a massive 2,000-foot-long earthwork which effectively seals off the end of the peninsula. Within the site archaeologists have identified the remains of a medieval field system and two Bronze Age barrows or burial mounds.

A trust ranger told me: "It was obviously a defensive site, but it will also have been a powerful status symbol. This is the biggest enclosed Iron Age structure – certainly in Cornwall – if not the whole of the country. There's 24 hectares enclosed altogether which is bigger than any other site of this kind.

"The other interesting thing is its continuous use," he added. "The various things we've found prove that.

"We have found Neolithic flints – so the site has been used continuously from the late Stone Age, through the Iron Age – then there are medieval field systems – and we come right up to the present day."

Out at the end of the headland there is a large cross which was erected as a navigational aid by a local rector late 19th century. The storm gods must have taken a dim view of it – they blasted the thing apart with a lightening bolt. What we see today is the original granite edifice that has been concreted over.

From the point you can look back east and see our beautiful beach looking cosy in its bay – on a still day you are given no hint of the peril this bit of coast can so easily provide. No other single site along the south coast of England is quite so rich – if that's the right word – in wrecks.

Apparently, The Dodman was particularly effective at sinking ships which had missed the entrance to Falmouth harbour. "In 1897, in thick fog, the destroyers Lynx and Thrasher struck the headland below the cross on their way from St Ives Bay to Carrick Roads," says the trust's booklet on the area.

"The loss of the pleasure boat Darlwin with 31 people in July 1966 has never been properly explained, but she went down in deteriorating weather off The Dodman. The Darlwin was returning to Mylor from a day trip to Fowey."

I strolled back to the beach to find I was the only human – clothed or otherwise – upon its handsome acres. But resume the 40 winks? You must be joking. I tried, but the calls of the oyster catchers translated in my fleeting dreams to the cries of those 31 lost souls.

Protected and perfect Vault Beach might be – but I swear it is haunted.