This article appears in Volume 21: The Islands Issue.

I I was 24 when I first went on holiday on my own. I stood at the harbour on Gili Trawangan in Indonesia and waved my best friend goodbye. I island-hopped for five days, then got the same boat back to Bali. It was a precious week; I had never spent more than a day on my own before, and it felt like a real exercise in independence. I got myself around and about without the help of a mate. I ate in restaurants on my own, I snorkelled on my own, I watched sunsets on my own, I learned to spearfish with local boys. I even managed to spend 48 hours in total silence - a first-time occurrence for a blabbermouth like me.

A few years later I went to Portugal on my own to spend a week learning how to surf (an experience that was immortalised in a Sunday supplement travel section with a photo of me falling off the board, looking like Miranda Hart). I've also visited New York on my tod twice. I love discovering all the hidden nooks of that city, even though I still can't get my head round its disastrous subway system.

I'm hooked on solo travel. I never feel as calm, as together, as self-reliant or as free than when I'm travelling on my own. It's where I have my best ideas - and it's where I can make sense of home.

But I've never gone into the wild on my own. In Bali I was surrounded by couples sharing plates of barbecued lobster or beachside massages. It was the same in Portugal (oh how fun it was to ask a honeymooning couple to help me get out of my wetsuit). In New York you're always surrounded by people. You can't find a square metre of uninhabited space, even in Central Park.

A trip to the Orkney Islands (never "the Orkneys", as I would later find out) is just what I need. I have long been fascinated by the Scottish islands - uniquely wild and remote, and sparsely populated, with endless miles of open sea and sky. I am feeling pretty anxious about writing my first book, and I am craving some space, peace and solitude to clear my head and get it into proper shape.

Flying into Orkney and looking down on all the islands floating in between the North Sea and the Atlantic, I realise why there is only an approximation of how many islands make up this archipelago. It is estimated that there are about 70, of which 20 are inhabited, but there are also allegedly "vanishing islands", magical mounds of earth that occasionally rise up from the sea. The airport - of which you could do a full tour in less than a minute - is in Kirkwall, one of two towns on Orkney's mainland, the other being Stromness. I am staying in the latter - a lesser-populated seaport town with cobbled streets and brightly coloured cottage doors.

Orkney's dramatic, primeval landscape has always been a source of inspiration for music, literature, art and discovery. Earlier this year, a three-part BBC documentary led by Chris Packham was aired in which he explored Orkney's wildlife, geology and Stone Age history. And last year, the Orcadian writer Amy Liptrot brought her homeland into the spotlight with her beautiful, evocative memoir about moving back to Orkney, after a decade of chaos in London, to recover from alcoholism and a broken heart. The book has been a runaway success, and the Orcadians are delighted for her. I meet one woman who tells me that they're in the same outdoor open-water swimming club, named the Polar Bears. I predict that plane-loads of people will start descending on Kirkwall for a full-healing "Outrun experience", just as Bali was swarming with 30-something single blondes looking for their Javier Bardem when I visited (the Eat, Pray, Love effect).

I am staying in the Ferry Inn, a warm and vibrant pub with old maps under glass table panes, black-and-white photographs of old seafarers on the wall, fresh local seafood on the menu and bottles of Orkney beer behind the bar. The rooms are simple but comfortable, with harbour views and an all-important powerful shower to warm yourself up after the bracing elements of the islands. I visit in spring and enjoy bright, crisp, sunshiney days with perfect golden sunsets as well as a bout of hail in my short stay. The summer, I am told, is a beautiful time to visit - with the long days never quite ending and nightfall only descending as a pale inky wash. It can remain light enough for locals to play a round of golf at midnight.

One of the most defining features of Orkney is that it is wrapped up in a rich, fascinating and often mythical history. There is evidence that the islands have been inhabited for 8,500 years, and stone circles, shipwrecks and early settlements are scattered everywhere. The famous Skara Brae is a stone-built Neolithic settlement that was uncovered by accident during a raging storm in the mid-1800s. What stands there now are the structures of a small village, and an insight into how this community would have lived, a hauntingly similar set-up to family life now - homes with a small crèche area, a fireplace in the middle of the room and a stone structure where they would display their most treasured items. No one knows why the community fled 500 years later, but I quiz a guide, and he tells me that he thinks it's because the sea poured into the loch, cutting of their fresh water supply.

Visiting the Ring of Brodgar, an ancient stone circle older than the pyramids, is a similarly moving experience. There is low-hanging mist on the morning that I visit, and two still lochs on either side. Again, what makes this piece of history especially mystical is that no one truly knows how it got there or what it was used for - some have suggested that it was used to tell the time, others that it was a place of theatre. Unlike Stonehenge, it is wonderfully unmonitored, and visitors are encouraged to go right up to the stones and touch them. Amy Liptrot writes in her book about how, as a teenager, she and her friends would go and drink on these Unesco world heritage sites once the tourists cleared off every day.

A 20-minute drive north of the Ring of Brodgar lies the Kitchener Memorial, which doubles up as a beautiful cliff side walk. High above the sea stands a tower built in memory of Lord Kitchener (of "your country needs you" fame), who lost his life alongside 655 officers when HMS Hampshire sank nearby. If you walk further along from the memorial you will find the perfect spot for bird-watching. I take a pair of binoculars and marvel at the thousands of guillemots - penguins in miniature - lining the spectacular cliffs. I am yet to see a seal, highly inquisitive creatures who the locals sometimes sing to, as the sound of human voices brings them closer (I am not averse to the idea of belting out a tune to see one). Other eccentric local animals are the famous seaweed-eating sheep of the most northern Orkney island of North Ronaldsay - their wool is the colour of the Orkney red sandstone and their meat is intensely gamey.

While walking along the cliffs I have my first experience of day- to-day island life when I say good morning to a passing walker, and she asks me if I was in the Ferry Inn the previous night. Yes, I reply. I thought so, she says. She remembers that I had the Shetland mussels and asks me how they were. Delicious, I say. Cooked in leeks and white wine. I love this tight-knit community feel of the island, and I think that it's one of the reasons why everyone seems so warm and friendly. (Incidentally, angry Groundskeeper Willie from the Simpsons is meant to have Orcadian roots, but I find his temperament to be vastly different to the islanders who I meet.) A local guy tells me that it would be impossible to have an affair here - it's hard to behave badly when you live on a fairly small island. That night I eat local vegetarian sausages with delicious clapshot (buttery mash made with potatoes and turnip) and drink two bottles of rich and boozy Dark Island beer (which I develop such a taste for that I end up visiting the local brewery and buying a few bottles to take home). The beer, along with the heady sea air, knocks me out, and I'm asleep by half past ten.

The next day I get a very early ferry to the second largest Orkney island of Hoy (Eurythmics fans may recognise it as the backdrop for the Here Comes the Rain Again video). I sit on the top deck and enjoy the bracing sea breeze while I look out at Orkney Mainland drifting further away. I am delighted when I finally spot a seal, which pops its head curiously out of the sea, takes a look around and then dips its head back into the cold water.

The journey is a quintessentially Orcadian experience, with the mobile library boarding the ferry (which goes to the smaller islands and has a high turnover of books, I'm assured) and a local radio DJ's voice that does the ferry's announcements. "Thank you for travelling with us," the man says. "We hope you'll join us again soon." A fellow passenger mutters: "We haven't really got a choice..."

Hoy is one of the most stunning places that I have ever visited, but it has a slightly different feel. With its dark earth of peat and its dramatic, undulating hills, it feels closer to a highland landscape. First I stop at Betty Corrigall's grave, a small white headstone looking out on to a loch and the wide, empty space of Hoy. The story of her death and burial, which I won't spoil for you until you've visited it, is a haunting, tragic and eerie tale - one that has inspired many songs, and one that sticks with me for weeks after I leave.

Rackwick Bay - on the west coast of the island - is breathtaking. Covered in large, glistening rocks washed emerald-green from seaweed, and with turquoise water lapping on the sand, it is unlike any other British beach that I have ever visited. It is not surprising that the novelist Will Self is said to have a place near here where he comes to write his books. Other than one small family further along the beach, I am completely alone. I sit on one of the rocks, breathe the ocean in, look out over mainland Scotland in the distance and feel completely at peace.

Hoy is most famous for its sea stack, which is known as The Old Man of Hoy, and - despite a sign warning "experienced climbers only" - I decide to walk high up along the cliffs to go see it. The walk only takes about an hour, and is entirely worth it. My vertigo can't quite handle the narrow jutting of cliff that is closest to the stack, so I crawl to it on my stomach and stare at the towering sandstone stack, the side of the rock made of layers that Liptrot perfectly describes as being like "the pages of a book". When I walk back I recover from my walk with a warming co ee and a tasty egg sandwich in the Beneth'ill Café.

That afternoon I head to the island of Lamb Holm to visit the Italian Chapel. This ornate Catholic church was built in the Second World War by Italian prisoners of war, who were captured and housed on the previously uninhabited island to build the Churchill Barriers (four causeways designed to provide naval defences). The chapel was constructed with limited materials - leftover prefabricated concrete huts and plasterboard form its bones, empty cans of bully-beef were carved into lanterns that hang at the altar. When the Italian prisoners left the island, the Orkney authorities promised to preserve and maintain the newly consecrated site. They have, and the result is a highly unusual building constructed with faith and love - I particularly enjoy seeing the black-and-white photograph of all the young Italian soldiers standing proudly outside their chapel, in this wild Scottish landscape that would have felt so far from home.

That night, after a few hours of quiet, undisturbed book-writing in my room, I lie in my hotel bed - my skin rosy and polished by sea air - and realise that I don't want to leave the next day. Tucked up under the covers, I get out my phone and look at Google Maps to see where I am right now. I look at where I lie, floating in the middle of the sea, and I zoom in to scan all the neighbouring tiny islands that I want to continue to explore. I want to keep travelling upwards, further and further, until I'm standing at Britain's very edge. I want to go to Fair Isle, with its population of 55, and stay in the lighthouse. I want to go to the Shetlands and get a plane to Foula to visit its school with three pupils. I want to fly up to the Faroes - the Danish islands in between Scotland and Iceland that I recently learned through a Radio 4 documentary are desperate for women for their men to marry. I learn the expression "island-bagger"- a person who visits as many Scottish islands as they can - and I get it. Sign me up. Count me in. I feel like an adventurer, I'm a convert to wild island life.

Orkney is the perfect place to travel alone, as you're never really alone there. There are the birds that outnumber the humans, the thousands of stars in the clear night sky and the remnants of life before today, the communities and homes that are thousands of years old. As I head back to London with half a book left to write, I feel connected to all of it - the earth, the sea, the sky, the wildlife, the stories and, most helpfully, myself.