St Columba's Cathedral

Stand on the Esplanade for a moment and listen. Gulls call over the water, halyards tap against masts in the bay, and a cool wind comes in off the sea with the smell of salt and seaweed. In front of you rises a wall of rough granite, grey with a warm pinkish tone, cut in heavy blocks. This is Saint Columba's Cathedral, and it looks less like a building than a piece of the coast that someone has shaped into a church.

This is the Roman Catholic cathedral of the Diocese of Argyll and the Isles. It is the mother church for a scattered community that runs from this small harbour town out across the islands of the west coast of Scotland. Few dioceses in Britain cover so much sea and so few people. Priests here have long travelled by ferry as often as by road. So the cathedral faces the water, and that feels right.

Here is the first surprise. Oban, a town of only a few thousand people, has two cathedrals. A short walk away stands Saint John's, the cathedral of the Scottish Episcopal Church. Most visitors walk past both without knowing this. For a town this size, it is unusual. It shows how important Oban became as a gateway to the Hebrides, the long chain of islands off Scotland's western coast.

The man who designed this building was Sir Giles Gilbert Scott. His name may not sound familiar, but his work almost certainly is. Scott designed Liverpool's vast Anglican Cathedral. He also designed Battersea Power Station in London. And yes, he designed the classic red British telephone box. The same architect who gave Britain its most familiar street object also gave Oban this quiet stone church by the sea.

Before this cathedral existed, the Catholic community of Oban worshipped in a much humbler building. It was a simple structure of corrugated iron, and locals remember it as the tin cathedral. Picture the rain of the west coast drumming on a metal roof during Mass. The granite building in front of you was meant to give the diocese something permanent, something that would last through centuries of Atlantic weather.

That permanence took patience. Work began in the early 1930s, and the building was not finished until the late 1950s. Those years included economic depression and the Second World War, when building materials and labour were scarce. So the cathedral was raised slowly, stage by stage. When you look at the walls, you are looking at the work of a whole generation, not a single season of building.

Now look up at the tower. It is square, broad and very solid. It does not taper into a delicate spire like many Gothic churches. Instead it rises in a strong block that suits this exposed coast. Scott worked in a modern version of Gothic style, which means he kept the pointed arches and tall proportions of medieval churches but stripped away much of the decoration. The result is simple, strong and calm.

The stone itself deserves a closer look. Walk up to the wall and touch it. The granite is rough-faced, left with an uneven surface rather than polished smooth. In grey weather it looks almost silver. When the evening sun comes across the bay, it warms to a soft pink. Granite is one of the hardest building stones, which matters in a town where storms come straight in from the sea.

If the doors are open, step inside. The change is immediate. The noise of the Esplanade falls away, and the air feels still and cool. The interior is tall and plain, with pale walls and high arches. There is very little clutter. Scott let height, light and proportion do the work. Your eye travels naturally down the long nave, the main central space of the church, towards the altar.

The cathedral takes its name from Saint Columba, an Irish monk of the sixth century. According to tradition, he sailed from Ireland and founded a monastery on the island of Iona, just off the coast of Mull. From there, Christianity spread across much of Scotland. Many stories about Columba are legend rather than recorded fact. Locals say he faced down a monster in the River Ness, which some people link with the famous Loch Ness tale.

Iona is not visible from here, but the journey towards it begins in this harbour. Ferries leave Oban for the Isle of Mull, and many pilgrims cross Mull to reach Iona. So in a sense, this cathedral stands at the start of Columba's road. When you watch a ferry pull away from the pier, you are watching the modern version of a very old sea route.

Step back outside and look across the water. The low green island just offshore is Kerrera, which shelters the bay from the open sea. Beyond it, on a clear day, you can see the hills of Mull. Behind you, on the hill above the town, stands McCaig's Tower, a circle of granite arches built in the late nineteenth century. Between them, the cathedral holds its place on the shoreline.

As you walk away, turn once more and look at the tower against the sky. Notice how the stone changes colour as clouds move over the bay. Listen again to the gulls and the boats. This building was made slowly, by people who expected it to outlast them. It is still here, still facing the sea, still open to anyone who comes in from the wind.