On paper, the crossing to the Isle of Mull is a simple journey – a 45-minute car ferry from Oban, on Scotland’s west coast, to the small island port of Craignure. In practice, it’s more than that. The world slows a little. The skies expand. Part way through the crossing, a sea loch furls out to the north and the hills and ridges of Mull come into focus ahead. The UK mainland recedes. In more ways than one, the ferry transports you.

Mull is the second biggest island in the Inner Hebrides, sitting some 25 miles south of the larger, and more visited, Isle of Skye. Its coastline is fiercely beautiful – a world of wild inlets, soft beaches and otter-patrolled bays – and its highlands swell up to above 3,850 feet, eulogised by hikers and overflown by eagles. On a fine day, and even on a grey one, Glasgow feels a long way away.

The most obvious focal point is Tobermory, Mull’s tiny but charming ‘capital’, where a row of gaily painted buildings – several of them pubs – frame a handsome natural harbour. As a result, many visitors see only the northern coastal road between Craignure and Tobermory, which is to miss out on a vast part of what makes Mull so magical.

Head further south and the rewards are huge. The roads narrow, the phone reception vanishes and the landscapes broaden. There are castles, cafes, galleries and gardens, but the backdrops dwarf the lot. Some of the views around the Treshnish Peninsula and the Ross of Mull are as sweeping and spectacular as you’ll find anywhere in Britain.

A trip here, however, is about more than just Mull itself. It would be a crying shame not to include Iona, the low-lying island hanging off Mull’s southwestern edge, and likewise the uninhabited islet of Staffa, which moved Mendelssohn to write an overture in its honour. Mull and its surrounding islands are full of evocative human stories – not least the 18^th and 19^th-century Highland Clearances, which saw the local population forcibly evicted – but the overriding motif of any visit lies in the formidable work of Mother Nature.

The Wild Isles

When porpoises appear over breakfast, you know it’s going to be a good day. I’m tackling a plate of smoked trout and scrambled eggs at Iona’s enjoyably unpretentious Argyll Hotel when I look out at the water and see three of them, their dark backs gleaming. Beyond, Mull is washed in sunshine. The animals swim slowly, taking their time. They have the right idea, porpoises.

People have been crossing from Mull to Iona for close to 1,500 years, ever since an Irish missionary arrived in AD 563 and used the island as a base to spread Christianity across Scotland. The man – now known as St Columba – gave rise to the island’s abbey, which continues to draw pilgrims. On my first night I follow a pub tip and end up at a 9pm service. There are chants, candles and Celtic crosses. It’s stirring stuff.

Iona by day is no less meditative. I walk out to the broad sands known as the Bay at the Back of the Ocean, where eider ducks are my only company. I spend an hour wandering out to the remote beach at St Columba’s Bay, where the waves roll in off the Atlantic and oystercatchers quickstep on the shore. And I climb the grassy hill of Dun I, where the sunset views are shared with a herd of stoic sheep and the ‘crek-crek’ rattle of corncrakes.

The next day I join a small boat heading out to Staffa, a striking little island jutting out of the sea on hexagonal basalt columns. We pass a colony of seals, lying fat and placid on rocks, then follow a trail up to the clifftops. Puffins are fussing around in their dozens. “They like humans,” says the boat captain, explaining why the birds are happy to waddle by just feet away. “The gulls and skuas clear off when we’re around.”

The region’s wildlife generally does the opposite of clearing off. Back on Mull itself I watch a golden eagle soaring above the hills, its fanned wings outstretched. Wild goats stare from under curved horns; great northern divers shape and shimmy offshore; wheatears and herons appear almost everywhere I go.

Best of all is when I drive along the slender road leading from Loch Beg to Salen. In the honeyed light of late afternoon, the views are near-celestial. I pull over to stare at the quiet hills and bays. The evening is still – all greens, golds and blues – and on cue an otter emerges, brown fur spiked and wet. For ten minutes I watch it dive and feed, the water rippling as the day dissolves. It shivers with life, Mull, and it knows how to conjure moments that stay with you.

Three of the best walks

Ben More

Mull’s highest point – and the only Munro outside of Skye and the mainland – is Ben More. It is unique in Scotland, in that any ascent has to start from sea level. The simplest route is an up-and-down from the shore of Loch Na Keal, but hardy hikers will enjoy the scramble up A’Chioch ridge.

Treshnish Coastal Circular

Regularly described as Mull’s most scenic coastal walk – and competition is stiff – this four-hour circular trail wends around part of the Treshnish Peninsula, passing old crofters’ villages and a cave once used for making whisky. The islands gathered offshore are a glorious sight. Park at the side of the B8073.

Carsaig Arches

This wonderfully secluded route leads you beneath tall sea cliffs on the island’s south coast, culminating in a pair of impressive natural arches. It begins at Carsaig Pier. Allow around six hours return, expect wildlife sightings and take care on the exposed section between the two arches.

Three essential Mull experiences

Join Mull Eagle Watch

The white-tailed sea eagle is Britain’s largest bird of prey. The species, often referred to as a ‘flying barn door’ thanks to its size, disappeared from Scotland around 100 years ago but has since been successfully reintroduced. This non-profit venture takes you to within binocular-distance of a nest, explaining the eagles’ habits and showing what makes the birds so renowned among wildlife-lovers. Book in advance. Runs from April to September.

Explore Tobermory

Virtually every visitor to Mull comes to Tobermory at some point. Wander the brightly-hued harbourfront then follow the woodland trail into nearby Aros Park, before returning to town. Eat at one of the pubs or try battered scallops and chips from the waterside fish and chip van. A place to stay? On the slopes above town, Strongarbh House is an elegant four-room hotel with a library full of art books and single malts.

Visit Calgary Art in Nature

The sheltered beach at Calgary is among the most popular spots on the island – and actually gave its name to the Canadian city – but there’s more to admire than its pale sands. Beginning a couple of minutes’ walk from the beach itself, Calgary Art In Nature is an outdoor installation of locally inspired artworks, dotted around the hills and woodland to create a thought-provoking walking tour – and some great views to boot.