Travel without a purpose is debilitating; the more obsessive and lunatic travel plans are, the better. A fortnight on a beach is fine if one is in the business of attracting a mate for breeding or whatnot, but otherwise it is rather dull. And now that both tanning and visiting coral reefs are illegal activities, any sane person should not be expected to spend whole days in the shade with Ian McEwan.

A trip is beneficial if it forces one to abandon one’s comfort zone, and leaves one so exhausted that weeping seems a good way to end the day. Activity holidays are absolutely the thing, but better still are quests. One weekend in a boutique hotel is fine. More, and one softens and sags. The modern traveller needs a mission, not a massage.

This is all by way of justifying my quest to discover the abandoned island of St Kilda: an 18-hour trip out of Oban in stormy, vomitrocious seas (even the ship’s cook was sick) on a metal-hulled Arctic rescue vessel. We spent a lot of time listening to the shipping forecast – Rockall, Malin, Hebrides, Bailey – because it mattered to our survival out in the Atlantic.

St Kilda rises out of the Atlantic like a volcano, and sailing into its horseshoe-shaped bay makes you imagine you are floating in the crater. It is the furthest inhabitable land in Scotland – only Rockall stands between it and Canada – and no one has lived there permanently since the last villagers were shipped off in 1930.

St Kilda is populated by tens of thousands of seabirds: puffins, fulmars, skuas sitting on sheer cliffs that rise hundreds of feet out of the water. Isolated and desolate, it’s not a five-star destination. You sleep in bunks on the boat, unless you are with one of the National Trust expeditions which are slowly preserving and excavating the abandoned village, low roofless stone cottages along grassy Main Street – the only street.

There are no trees on St Kilda – the winds are too strong, and the villagers made coffins from shipwrecks and driftwood. But you can walk through fields of wild flowers and up beautiful slopes spotted with hundreds of grey cleits, domed stone stores like little igloos, from the days when the islanders lived on dried fulmar and puffin porridge.

The St Kildans climbed barefoot up the sheer cliffs, killing birds and gathering their eggs to survive. Over hundreds of years, they adapted to the job. There is a species of St Kilda wren, a St Kilda mouse, and there is, it’s said, a St Kilda toe, an elongated big toe that let the men cling more easily to the crevices in the rocks. On our Northern Light Charters boat out to the island, one of the men was the son of a St Kildan woman, who left as a child. We were agog when he got on his trek sandals – his big toe was preternaturally enormous.

So in many ways, travel doesn’t get as weird, romantic, or Darwinian in these modern times. And once you’ve been to an uninhabited Scottish island, you get a taste for them. In my daggy Scottish Islands Explorer magazine, I came across the wonderful story of Andy Strangeway, a decorator from Pocklington in Yorkshire, who at the end of August finally conquered Soay, one of the tiny islands in the St Kilda group, ending his four-year quest to spend the night on all 162 Scottish islands.

He is hoping that visiting all the Scottish islands (more than 40 hectares, to eliminate mere rocks) will be known as “doing the Strangeways” just as “bagging Monroes” became the term for climbing all the Scottish mountains over 3,000ft. Around 100 of the islands are uninhabited, although one has to be careful about Gruinard, the anthrax testing site, only reopened a few years ago. Skye, says Strangeway, no longer counts since it went mainstream and got a bridge.

On his website, Island-Man.co.uk, Strangeway explains his madness: “Beyond this great adventure, there is something far greater, something that I cannot see. I can only feel it and I do not know of what I talk. My time on the islands has brought out an awareness deep within me. I have no firm belief in a religion or God, but I still seek. I am aware that all these islands have a presence and, the more isolated the island is, the stronger this presence becomes.” When did they last say that about the Costa de Sol?

The Strangeways are unbelievably tempting. I’ve a dozen or so Scottish islands already under my belt, but most of those were reached by Caledonian MacBrayne. The uninhabited ones require more ingenuity. So along with my husband, I am taking the RYA Day Skipper Theory Course, in preparation for the practical, so we can rent boats and navigate treacherous waters – perhaps by the stars when the sat-nav goes down. It’s three hours in college every Monday night all winter, but now I’ve seen all 148 episodes of The Sopranos what else is there to do but dream?

kate.muir@thetimes.co.uk