St Mary's Cathedral, Sydney

Put your palm flat against the stone. It is cool, slightly gritty, and the colour of dark honey. When the afternoon sun reaches it, the whole wall seems to warm from gold to amber. This is Sydney sandstone, cut from the same ground the city stands on. You are standing beside St Mary's Cathedral, the seat of the Catholic Archbishop of Sydney. Above you, two spires rise against the sky, and the traffic noise from the street seems to fall away a little.

This cathedral began with a small and uneasy community. In the early years of the colony, many convicts were Irish Catholics. For a long time, they had no official priests at all. In 1820, two priests arrived with government approval to serve them. Soon after, land was granted on this ridge at the edge of the town. A first stone church rose here in the 1820s. It was modest by later standards, but it gave the Catholic community a fixed place of its own.

Then came disaster. In 1865, fire swept through that first church and destroyed it. Accounts describe the roof falling in and the interior burning out within hours. For the community, it was a heavy loss. But the archbishop of the day did not settle for rebuilding the old church. He wanted something far larger. He turned to William Wardell, an English-born architect working in Melbourne. Wardell had already designed major church buildings in Victoria, and he knew the Gothic style closely.

Gothic Revival was the style Wardell chose. It is a nineteenth-century return to the pointed arches, tall windows and ribbed vaults of medieval European cathedrals. Look at the windows on the side walls. Each one ends in a pointed arch, not a round one. The buttresses, the stone supports that step out from the walls, carry the weight of the roof outward and down. This is a medieval engineering idea, rebuilt in Australian stone, on the far side of the world.

Here is the first thing many visitors miss. Most traditional cathedrals run from west to east, so the altar faces the sunrise. St Mary's does not. Because of the shape of the site, the building runs roughly north to south. Wardell worked with the land he was given. If you have a compass app on your phone, try it now. It is a small detail, but it shows how practical decisions shaped even a sacred building.

Building something this large took a very long time. The foundation stone for Wardell's cathedral was laid in 1868. Work then continued in stages over many decades, as money allowed. Wardell himself died in 1899, long before the building was complete. The main body of the cathedral was finally finished in the late 1920s. Even then, it was not quite the building he had drawn. Something important was still missing from the skyline.

That missing piece was the spires. Wardell's plans showed two tall spires on the southern towers. For most of the twentieth century, those towers simply stopped short, flat at the top. Generations of Sydney people knew the cathedral that way. The spires were only added in 2000, the year Sydney hosted the Olympic Games. So the tops of the towers above you are far younger than the stone below them. Try to spot the slight difference in colour.

Now step inside, if the doors are open and no service is under way. The air changes at once. It is cooler, quieter, and smells faintly of stone and wax. The nave, the long central space where the congregation sits, stretches ahead of you. Light enters through stained-glass windows, and much of this glass was made in England. On a bright day, coloured patches of red and blue move slowly across the floor and the pillars as the sun travels.

Take a moment with the windows. They are not only decoration. In earlier centuries, many worshippers could not read, so windows told stories in pictures. Here you can find scenes from the life of Christ, figures of saints, and images of Mary, to whom the cathedral is dedicated. Stand at the back and let your eyes adjust. The details become clearer the longer you look. Small faces, hands and patterns appear that you will not notice in a quick glance.

The second surprise is below your feet. Beneath the cathedral lies a crypt, a lower chamber used for burials and quiet worship. Its floor is a large mosaic, made from many small pieces of stone. The design follows the Celtic style of early Irish manuscripts, with looping lines and knotwork. It tells the story of the Creation. This Irish style is a deliberate link to the community that built the church. Check at the entrance whether the crypt is open during your visit.

The cathedral has also been a stage for large public moments. In 2008, Sydney hosted World Youth Day, a major international Catholic gathering. Pope Benedict the Sixteenth came to the city, and the cathedral sat at the centre of events. Crowds filled the streets and parks around it. Today, the building is busy in quieter ways. Weddings, funerals and daily Masses continue here. When you visit, remember that this is a working church, not only a monument.

Outside again, look at the setting. The cathedral stands at the edge of the city centre, close to the green space of Hyde Park. Office towers of glass and steel rise nearby, and their cool surfaces make the warm sandstone look even richer. In the weeks before Christmas, the great southern front becomes a screen. Large coloured light projections are shown on the stone after dark, and families gather on the forecourt to watch.

Walk a short way back and turn around. From a distance, you can see the whole shape at once. You see the long roof, the towers and the young spires on the old stone. Notice how the colour of the sandstone changes with the time of day. In the morning it looks pale. By late afternoon it turns deep gold. Each block was cut, lifted and set by hand, over many decades, by people who never saw the finished building.

So before you move on, pause here for a moment. Listen to the birds in the park, the buses on the road and perhaps a bell above you. Look once more at the line where the old towers meet the new spires. That line holds more than a century of patience. As you walk away, you will see this same honey-coloured stone in other old buildings across Sydney. Now you will know where to look.