Ten days in Finland: from the Baltic to the Arctic Circle on one railway line

Start at the sea end of Esplanadi. The park is a strip of lawn and lime trees between two boulevards running up from the harbour, and in summer the whole city sits on it, with a free concert most evenings on the stage at the water end.

The Old Market Hall is the low red brick building on the quay, open since 1889 and the best eating on the waterfront: one aisle of stalls doing smoked fish, reindeer, cheese and soup, with counters to sit at. Outside on the cobbles the open air stalls sell berries all summer, and the thing to buy in July is a bag of sweet green peas that you pod and eat raw as you walk.

Then climb Senate Square in the evening light. Engel's white, green domed cathedral was finished in 1852 and stands at the top of a very wide flight of steps with the twelve apostles along the roofline. It is better outside than in, which is convenient since the interior now costs money and is austere even by Lutheran standards. The three sides below, the university, the government palace and the merchant's house, were designed to make a town of a few thousand people look like the seat of a grand duchy, and they look so convincingly Russian that Cold War film crews used the square as St Petersburg.

Uspenski Cathedral is ten minutes from the market square, up a rock on the Katajanokka side of the harbour, and you will already have seen its red brick and five gold domes from every waterfront view. It serves Finland's Orthodox minority, a leftover of the Russian century, and the dark icon heavy interior is a shock after the whitewashed cathedral of last night. Twenty minutes. Closed on Mondays.

Then take the boat out from the market square quay. Suomenlinna is a fortress spread over six linked islands twenty minutes offshore, and the ferry runs on an ordinary HSL ticket, the same one that works on the trams. Sweden began building it in the 1740s at ruinous expense to hold its eastern flank and called it the Gibraltar of the North, then lost it in 1808 without much of a fight: the Russians besieged it, no relief arrived, and the commander Carl Olof Cronstedt surrendered after two months. Finland was ceded shortly after, Cronstedt was condemned as a traitor by a king who was himself soon deposed, and he lived out his years gardening.

It rewards a whole day because eight hundred people live out there, with a school and a shop, and the ramparts, dry docks and tunnels are simply their landscape. Take the blue signposted route across the bridges to the King's Gate at the far end and come back along the southern shore, where the cannons face the open sea and people swim off the rocks in July. The Ehrensvärd Museum in the commandant's house is the one indoor stop worth making: it belonged to the man who built the fortress, and he is buried in the courtyard outside.

Temppeliaukio was quarried straight down into a granite outcrop in a residential block of Töölö and finished in 1969. From the street you see almost nothing, a low copper dome sitting in the rock. Inside, the walls are the blasted rock face left rough and the ceiling above is twenty two kilometres of copper strip wound in a spiral. It is one room and it takes fifteen minutes, but the acoustics are so good that a concert there is a different experience entirely. Arrive at opening; the coach parties come mid morning and the space is small.

Walk back towards the station for Oodi, which Helsinki built in 2018 directly facing the parliament and meant every bit of the implication. The ground floor is a café and a hall, the middle floor holds 3D printers, sewing machines, recording studios and kitchens anyone can book, and the top floor is one white curve of reading room under a wooden hull with a terrace looking at the government quarter. It costs nothing and it is the best free interior in the country.

The Ateneum, two minutes further, is the national gallery, and it is the place to see what Finnish artists did with a national identity that was still being invented. The strength is the room of the late nineteenth century: Gallen-Kallela's scenes from the Kalevala, Helene Schjerfbeck's self portraits thinning out towards the end of her life, Edelfelt painting Paris and Porvoo with the same brush. Two hours covers it comfortably.

Two hours on the train, roughly hourly, through farmland and forest. You arrive at a station ten minutes north of the market square in a city that was the capital of Finland until 1812, when Russia moved the government to Helsinki because Turku was too Swedish and too far west. Fifteen years later a fire that started in a kitchen destroyed about three quarters of the town in a single night, which remains the worst urban fire in Nordic history, and everything you walk through afterwards is on a new grid of wide firebreak streets.

Turku Cathedral survived it, more or less. Consecrated in 1300, it is the national shrine of Finland and the mother church of the Finnish Lutherans, and the side chapels hold bishops, generals and one queen, Karin Månsdotter, a soldier's daughter who married Erik XIV of Sweden and finished her life on a Finnish estate. The bells are broadcast at noon across the whole country, and on Christmas Eve they are what Finland listens to.

The Old Great Square, three minutes downhill, was the centre of the city until the fire, and the four restored mansions around it are what a merchant town looked like before the grid.

Then go underground. Aboa Vetus was found by accident in 1992 during work on a shipping magnate's house, and the excavation turned up a whole block of the medieval town: cellars, streets, a well, the foundations of houses buried when the city was levelled. You walk on the medieval street level several metres below the present one, and the same ticket includes the contemporary art half upstairs.

Luostarinmäki is what Turku looked like before 1827. It was the poor quarter on the hill, wooden and cramped and outside the town proper, and it was the only substantial part of the city the fire did not reach. Rather than clear it, Turku preserved it, and it is now a handicrafts museum where over thirty workshops stand on their original sites, which is close to unique among open air museums: nothing here was moved in from anywhere else. In summer there are craftsmen working in them.

Then walk downstream. The riverside path runs three kilometres from the town to the sea, flat the whole way, past the moored boats and the free ninety second ferry that has been crossing since 1904.

Forum Marinum sits on the west bank near the bottom, holding the national maritime museum and the navy museum, but the ships moored outside are the reason to come: Suomen Joutsen, a full rigged three master built in France in 1902 and used as a training ship, and Sigyn, a wooden barque of 1887 and the last of her kind afloat, plus minelayers and small craft. The ships open in summer only.

Turku Castle is five minutes further, at the river mouth beside the Stockholm ferry terminal. Building began in the 1280s and it grew over three centuries into the largest castle in Finland, a grey stone block with a Renaissance floor added by the dukes who held it. It has been a fortress, a royal residence, a granary, a prison and a bombing target. Two tours run through it, one medieval and one sixteenth century, and the staircases are steep and narrow with very few short cuts.

An hour and three quarters north east through lakes and forest brings you to a station at the eastern end of Tampere's main street, with the whole city downhill from it.

Tampere Cathedral is ten minutes uphill and looks from outside like a granite fortress: Lars Sonck, finished in 1907, National Romantic at its heaviest. Inside, Hugo Simberg painted the walls, and nothing about them is conventional. A procession of naked boys carries a garland of thorns around the gallery. Three black robed skeletons tend potted plants in a work called the Garden of Death. And in the transept is The Wounded Angel, two boys carrying an injured angel on a stretcher across a bleak landscape, once voted the national painting of Finland and never explained by the artist. The church council objected at the time and was talked round.

Walk back down to the water. The Tammerkoski rapids drop eighteen metres between the two lakes that Tampere sits between, and that drop is the entire reason the city exists. The park along the channel is where the town sits in summer, and standing on the bridge looking north gives you mills, chimneys and water in one view.

Then cross into Finlayson. James Finlayson, a Scottish engineer, started a cotton mill on the west bank in 1820, and the site grew over a century and a half into a walled industrial town with its own church and power station and thousands of workers; the first electric light in the Nordic countries burned in its weaving hall. The mills closed and the buildings were converted rather than demolished, so what you walk through now is a red brick courtyard full of restaurants, cinemas, shops and museums.

Vapriikki is the main museum of the city, in another converted factory on the east bank. Calling it one museum understates it: there are ten or so exhibitions under the roof, including the Finnish Hockey Hall of Fame, a natural history museum, a shoe museum and rotating shows on Tampere's own history, which are usually the best thing in the building and cover the 1918 civil war. Tampere was the Reds' capital, and the battle for it that spring was the largest ever fought in the Nordic countries.

Amuri, ten minutes west, is the other half. It is a block of wooden workers' houses from the 1880s preserved on the spot, with the courtyard, the shared kitchens and the outhouses, furnished room by room to show how a mill family lived in the 1880s, the 1910s, the 1930s and on up to the 1970s. The arithmetic is what lands: several families to a house, one stove between them, and the factory whistle running the day.

Then go to Pispala for the sauna. Rajaportti opened in 1906 and is the oldest public sauna still working in Finland, in a low wooden building on a corner of the ridge between the two lakes. The stove holds over a ton of stones and is fired with logs for a couple of hours before opening, which produces a soft heavy heat that electric saunas cannot reproduce and that Finns will argue about at length. Separate men's and women's sides, towels for rent, and the thing to do between rounds is stand outside on the pavement in whatever the weather is doing, along with everybody else.

This is the big travelling day and it is worth doing in daylight at least once. Seven to eight hours north from Tampere through Oulu, watching the forest change: pine and lake at first, then thinner birch, then the flat expanse of southern Lapland. There is a restaurant car. If you would rather sleep through it, the overnight service covers the same ground with cabins that have their own shower, and it is the more popular option.

You arrive in a town that was built twice. In October 1944 Finland changed sides and the German army stationed in Lapland burnt Rovaniemi as it withdrew, destroying something like nine tenths of the buildings. Alvar Aalto drew the reconstruction plan in 1946, and the streets he laid out form, on a map, the outline of a reindeer's head with the sports stadium as the eye. Whether he meant it is still argued about here.

Walk down to the Kemijoki for the evening. The Jätkänkynttilä bridge crosses at the north end of the centre and its single tall pylon carries a yellow flame at the top, lit at night. A jätkänkynttilä is a lumberjack's candle, a split log stood on end and burnt from the inside, which is what the loggers used to light their camps along these rivers when the whole town lived off floating timber.

Arktikum is the reason Rovaniemi deserves a day rather than a stopover. It is a glass tube a hundred and seventy metres long driven out of a hillside towards the river, with the exhibitions buried beside it under the ground, and it holds two museums at once: a science centre about the Arctic as a region, its climate and its light and how both are changing, and the provincial museum of Lapland, covering the Sami and the history of this specific place including the burning and the rebuilding. The Sami material is made with the Sami rather than about them, which is not universal. Two hours, and the glass corridor is genuinely cold in winter.

In the afternoon take bus 8 out to Santa Claus Village, seven kilometres north. It is a tourist trap and almost nobody skips it. It stands on the line of the Arctic Circle as calculated when the place was built, which has since drifted a couple of kilometres north because the earth's tilt wobbles, so the painted line on the ground is both the reason everyone is there and slightly wrong. Santa is on duty every day of the year. The genuinely good part is the post office, which has its own postmark, handles hundreds of thousands of letters addressed to Santa a year, and will hold a card you post today until Christmas.

Stay out there into the late afternoon for the reindeer. Several farms operate at and around the Arctic Circle with a short sleigh ride, a chance to feed the animals lichen, and someone who herds them for a living explaining what that involves in a country where reindeer husbandry is a legal right rather than a hobby. Book ahead between December and March.

Ounasvaara is the fell across the river, twenty minutes' walk from the centre and two hundred metres above it, and it is where Rovaniemi goes outdoors: thirteen downhill runs and a hundred kilometres of cross country track lit through the dark months, trekking and mountain biking in summer. From the top you get the town, the two rivers meeting below and unbroken forest to the horizon in every other direction, which is a better last image of Finland than the airport.

If the weather has closed in, the alternative is Korundi, an art museum and concert hall in a bus garage of 1933 that is one of the handful of buildings the Germans left standing. The collection is modern Finnish art and the Chamber Orchestra of Lapland plays there.

The airport is a short bus ride, on the same line 8 that goes to the Arctic Circle.