My journey to the uninhabited Scottish island that is yours for £500,000!

There is something splendid about standing on top of the rugged, lichened, 89-acre kingdom of Mullagrach; tasting the salt on my lips from the sea spray, watching the cormorants swirl, listening to the skylarks sing and knowing there’s nothing but water between me and the North Pole.

Oh, how very wonderful it must be to be rich. Because this glorious spot — a teeny island, all cliffs and coves, crags and shags and flowering sedums, and perched right on the northernmost tip of Scotland’s Summer Isles — is up for sale. And it could be mine, or yours, for half a million pounds.

Plus a bit extra for a sturdy boat to make the 35-minute crossing from the Old Dorney Harbour on the mainland. And another £395,000, if I fancied snapping up Mullagrach House back on the mainland, to have somewhere comfy and cosy to wait, and wait, and maybe wait a bit longer, for the sea to be calm enough to cross to my very own island.

Because, as always, there’s a teeny-weeny catch — this gorgeous Highlands and Islands utopia is not brilliantly accessible.

In fact, at the moment, the only way to get on to it is to climb a rickety-looking series of very vertical, rusty ladders, from a bobbing boat. Until, that is, the wind gets up and the swell reaches a metre high — which happens alarmingly often, thanks to the vigorous northerlies here — and then it’s too dangerous.

Which means that, as well as being very rich and somewhat agile, any potential purchaser will need to be extremely patient, too — even just to view the island.

Phiddy Robertson, of Galbraith estate agency, who has sold a few islands in her time and is handling the sale, puts it like this: ‘On this island, nature is in charge. So if nature decides that the wind is too wild or the swell is too great, then you can’t land. Which is a very humbling and grounding experience and makes it so special.’

She’s not joking. We waited nearly three weeks while our lovely boatman Steve Husband, 63, checked his trusty weather-forecasting app — Windy.app — on his phone, updating us every few days. ‘Too windy… too much swell… not for the foreseeable… maybe next week — I’ll find you some dolphins…’

But finally on Wednesday, after a three-hour drive from Inverness admiring the lochs and wild lupins, we were scudding across the water in Steve’s orange boat in the bright sunshine towards the island.

We had strict instructions from the vendor, Chris Bown, that this was to be a day trip only. Because, well, there’s always a risk with Mullagrach that, even when you finally get there, the wind will change and leave you stranded.

One previous owner became marooned here with his son for the best part of a week.

The swell was too high, winds too fierce and the pair were left cowering in the only man-made cover on the island, an unpleasant plastic shelter, until they were finally rescued by the coastguard.

‘They were stuck for days,’ says Steve. ‘You wouldn’t have wanted to be in that thing for a minute. It had no windows and it stank.’

Not surprisingly, within hours of them staggering back onto dry land, the island was up for sale. ‘They weren’t ever going back,’ says Steve.

Chris, who bought it back in 2006, tells me his longest stay was four days. ‘A bit longer than I’d planned,’ he says, though he had at least built a cabin by then — more of which later. ‘You just have to go with it, but it’s a very special place.’

And as we haul ourselves up a rusty ladder (constructed by Steve) and climb out onto the grass, it feels almost shockingly pristine and perfect. As if the volume has been cranked up on our senses.

The smells of heather and bracken. The turf, so green and springy and soft it feels like a fairy mattress.

The taste of salt and fish and honeysuckle in the air. The swoosh of the waves on the rocks below. The wind. The loud caw, caw, caw of the cormorants and the sweet, sweet song of the skylark.

‘Sometimes the birds are so bloody loud you can’t hear yourself think,’ says Steve.

At the last count, there were at least 22 kinds of bird — including great skuas, kittiwakes, shags, fulmars and geese — as well as two resident otters and more than 95 species of plant or flower, from juniper to orchids, flowering moss to campion.

And on a good day, with a sharp eye, you can spot seals, porpoises, dolphins and minke whales.

‘It’s a great spot for watching the Northern Lights and, if you look really hard, you might see the North Pole…’ smiles Steve.

Not forgetting, of course, Chris’s cosy ‘high-quality, low environmental impact’ cabin, which was made in Switzerland out of super-strong cross-laminated timber.

It was erected on the island — mainly by Steve, by the sound of it — in 2016 and has everything you could possibly need: log burner, solar-powered fridge, hob, compost loo, two bunks with a stack of carefully curated reading material, and a very welcoming cupboard full of wine, beer, gin and emergency food.

The only thing it doesn’t have is Wi-Fi — and while Chris says it would be possible to have it, he clearly can’t think of anything worse.

For him, buying the island was always about respecting its unspoilt wildness by doing as little to it as possible.

Of course, if you really wanted to, you could make a few changes.

Development would be strictly limited, but if you had money coming out of your ears, you could clear the boulders in the teeny bay and put in a landing jetty.

Or just forget about boats altogether and slap a helipad on the bouncy moss and chopper in and out from Inverness Airport.

Though both Steve and Phiddy sound horrified at the thought. ‘That would be completely missing the point,’ they say.

‘This is not about fast living or convenience. It challenges you and brings you back in touch with something more honest,’ adds Phiddy. ‘Just enjoy it.’

On a bright, sunny summer’s day, it’s hard to imagine anywhere more perfect. But, according to Steve, that’s the trap.

Yes, the summers are long and light — around midsummer you can sit outside and still read a book at 11 o’clock at night — and fantastically energising, if prone to midges. But they’re also unreliable.

‘You could buy it tomorrow and it could rain for the next month,’ he says. ‘The best thing to do is go away and never come back and remember it exactly as it is today.’

Meanwhile, the winters are, well, monsters. Wet, wild and often dark by 3pm, with winds so strong that Steve shows me ‘wool’ — a sort of soft wooden fur on the outside walls of the cabin, made as the ferocious south-westerly gales erode the special reinforced Swiss timber.

Even though he has spent years living on Scottish islands, he wouldn’t dream of dwelling here.

‘Never,’ he says. ‘What would you do? What would anyone do?’

Until about 20 years ago, sheep still grazed here. The Summer Isles are so named because, historically, shepherds used to pop their sheep on them for summer grazing. There are still the remains of a shepherd’s hut on the north side of the island and, well, that’s about it.

To the south, the much bigger island of Tanera Mor — the inspiration for the cult 1973 horror film The Wicker Man — is a different kettle of fish.

It was bought in 2017 by English hedge-fund mogul Ian Wace, who is turning it into an upscale retreat. It has already welcomed Prince William and Princess Kate and TV presenter Ben Fogle ashore as visitors, and Ian has further plans to expand.

But Mullagrach has always been about preserving a bit more solitude than most of us would know what to do with.

While Chris is sad to sell, he knows it is time — he has four adult children battling with property prices.

Steve’s theory is that Chris’s wife was never quite as keen on it as he was — and I do note that there is just one toothbrush in the cabin.

But Chris adores and respects the island — unlike some of Mullagrach’s previous owners. Before Chris, a hotelier called Howard was bursting with grand plans. ‘A six-bedroom house, a swimming pool!’ says Steve. ‘There’s no bloody water here. He even got a water diviner in.’

According to Steve, Howard barely spent two hours on the island during his ownership. ‘Back then there was no landing frame so I’d bring a ladder in the boat,’ says Steve. ‘And he was a very fat chap, so it wasn’t easy and we never saw him again.’

So back on the market it went. At one stage, it was the property of lawyer Ian Macdonald. He adored it and the mainland community adored him.

But his family were less keen on the island. So, after he left it to them in his will on the understanding it would never be sold, it was on the market about 20 minutes later.

Lord knows who will buy it now. Hopefully not another silly Howard full of ambitions as mad as they are bad.

According to the agents, there has been a lot of interest, all from south of the border, or from abroad. But no viewings. ‘We won’t take anyone out there until they’re pretty committed to buying it,’ says Phiddy. ‘Though there is a very detailed drone video.’

Naturally, everyone in the mainland village of Achiltibuie likes to theorise on who will buy it.

‘Hopefully someone who’ll help in the community garden,’ says one lady.

The one thing they do agree on, everywhere I go — in the shop, down to the beach, in the very welcoming bar at the Summer Isles hotel — is how great Chris has been.

‘He’s proper. He’s thoughtful. He’s not like the others, who spend millions and only come every couple of years.’

But perhaps, most of all, the buyer needs to be someone familiar with the vagaries of the Scottish Highlands — to know that it could rain and blow for weeks on end. That life folds up in the winter, and often in summer, too. That sometimes you just have to sit out a storm and have another whisky, or five, and just relax and revel in the sort of extreme solitude that most people can only dream of.

But please, please, no one who wants to add it to their global property portfolio and chopper in once a year just to try to spot the Northern Lights.