Sankha Guha explores Finland's wild and watery frontier with Russia

Karelia poses a couple of seemingly innocent questions.

Where is it? And what is it? The answers, however, are not easy. Karelia is in eastern Finland, but also substantially in western Russia. Parts of it were ceded to Russia after the Winter War of 1939-40 and that remains a sensitive area for some Finns. Though it has a distinct cultural identity of its own, Karelia is the locus of Finnish nationhood – the wellspring of The Kalevala, the national epic poem. The one simple fact of the region is its untamed natural beauty. By contrast, its history, geopolitics, arts and religion are, both metaphorically and sometimes literally, Byzantine.

My first stop brings this home. The Valamo Orthodox Monastery is not in Valamo. The real Valamo is on an island in Lake Ladoga more than 100 miles away in Russia. The only Orthodox monastery in Finland was placed here as a result of that war with Stalin's Russia. Facing the Red Army onslaught, the monks evacuated the 800-year-old Russian Orthodox institution on Valamo, bringing a treasure of religious artefacts with them.

The displaced monks bought an old manorial estate among the forests and lakes of Heinavesi in western Karelia, and set about re-creating the Valamo monastery. The first church they built on site is a charming improvisation situated in a hall created by joining two buildings on either side of the driveway to the old manor house. The engineering is cheap and cheerful, evidenced in the ramped floor to connect the different ground levels of the two farm buildings. The walls and ceiling are faced with stripped pine. The rich glint of gold and colour emanating from the paintings and icons that crowd the walls seems at odds with the rusticity of the space. As church buildings go, it is decidedly unorthodox.

The monastery complex today is a popular tourist attraction. It includes guest houses, a hotel, a large conference centre, library, state-of-the-art icon conservation workshop and a sizeable gift shop with handcrafts and a range of berry wines made by the monks. In summer, coach parties descend and the monastery's claim to provide "a tranquil atmosphere in which to escape from the bustle of the modern world" is tested.

But there are transcendental moments to be found at the new Valamo even in high season. When the coaches have left and the guests have retired to bed I sit on the lake shore in the summer twilight. It is midnight and the silence is enveloping. I can hear the wing beats of a bird 200 yards away. There is a dying red tint on the western horizon; the water is like molten glass with steely greys and blues congealing slowly into each other. A bat swoops and dives soundlessly through the foliage on the water's edge – it is barely a smudge of disturbed air.

Then a hum grows in the distance. The hum magnifies to a roar and obliterates all else. It is huge and voracious. The beast of Valamo turns out to be a solitary lorry driving along the adjacent country road. It screams past and the receding rumble is accentuated by the returning stillness. The lorry is a reminder of the noise pollution that passes unnoticed in city life.

The next day in Ilomantsi, close to the Russian border, I meet Father Heikki Huttunen, Orthodox priest and general secretary of the Finnish Ecumenical Council. He shows me around the Orthodox graveyard, which is a wooded peninsula jutting into another glorious lake. The forest floor is covered in pine needles and a moving carpet of huge ants. There is little evidence of the cemetery. Father Heikki explains that traditionally graves were marked with wooden memorials and when there was no one left to tend them they were simply allowed to decay back to nature.

There are a handful of stone memorials, one of which is on the grave of a man "murdered" (according to the inscription) in 1918 – the year after Finland gained its independence from Russia. It was a time of tension between the majority Lutheran church and the Orthodox community (which was often associated with Russian imperial rule). The unfortunate man was executed as a suspected Bolshevik by the Finnish police. Father Heikki says he wasn't any such thing. He adds the churches get along fine these days.

Russia still looms large in Karelia. On the way to the village of Mohko I take a wrong turn and find myself on the edge of no man's land. The sign is blunt – "Stop" – it is accompanied by a graphic of a large red hand. The message is elaborated in five languages: "Border Zone. No entry without special permit."

There is a homespun museum in Mohko dedicated to the 19th-century ironworks that once existed here, but it is more significant as the former frontline during the Winter War. In the nearby Petkeljarvi National Park, the peace of the nature trails is challenged by the remains of trenches that were dug as defensive positions in the event of a Soviet breakout. The trenches were never used in earnest – the Finnish lines held. But the history of the bitter contest for Karelia is etched into the soil.

In Patvinsuo, another national park further north, guides Marko and Leena take me on a five-hour hike through a peat bog. It is in effect a giant sponge. We "walk the plank" – most of the hike is on narrow lengths of spruce or pine raised above the squidgy bog. Marko and Leena point out various flora en route, including tiny flytraps and a poisonous rhododendron that looks like rosemary. The return route is through woodland that is scattered with orchids and mushrooms.

We get to Lake Suomu in time for sunset. It is 11pm. At this latitude in summer the sun is in no hurry. An astonishing palette lights up the sky and the mirrored surface of the lake. God is jiggling his kaleidoscope every few minutes; creating new fractals of blazing golds and oranges, vivid pinks and purples, cold metal and icy mauves. At 1am I set off on the dirt road from Patvinsuo to Lieksa which climbs up a razor-edge ridge, wriggling and twisting, with steep drops on either side. Water is visible through the pines, catching the beams of a full moon. Mist is forming in thin wisps and settling on the lakes. It is an exhilarating drive, in the half light, between worlds, between myth and reality. It is the domain of bears, lynx and wolves.

To catch a glimpse of the notoriously shy wildlife of the taiga requires luck. Finland is the most heavily forested country in Europe; nearly 75 per cent of the land provides dense cover for the surprisingly tiny populations of the larger mammal species. The big predator species are still hunted in the country which must also contribute to their nervousness.

At Era Eero, which means Eero's wilderness, Eero Kortelainen has built a huddle of hides deep in the boreal forest to enable wildlife photographers and enthusiasts to get close to some of Europe's most spectacular beasts. His emblem is the vanishingly rare wolverine – a badger sized animal that looks bearish but is most closely related to the pine marten.

The hide is on a hillside next to a small lake. The whole area is pungent with the smell of rotting meat. About 30 yards away a pig's carcass, crawling with maggots, is dumped and tethered in a pit. One of the staff, the also bearish Hannu, darts around the area hiding fresh chunks of meat in nooks in the trees and under stones. All the while we are ordered to maintain silence.

The inside of the hide is basic but comfortable enough for the overnight vigil we are about to begin. Soon a disparate bunch of seagulls shows interest in the food. Then the ravens arrive; they gather on a log, trying to pry little chunks of meat from the hiding places. Noisy squabbles break out over the pecking order. For long hours nothing much happens. We speak in whispers and scour the unchanging scene for signs of animal life. Every once in a while the reek of rotten pig drifts towards the hide when the wind shifts. It is the smell of death. And those cuddly teddy bears love it.

At precisely two minutes to 10 an urgent hiss from Hannu alerts me. I peer out at the margins of the forest and see nothing. As my eyes adjust, a patch of shaded woodland appears to detach itself from the forest. Viewed through binoculars the shadow solidifies into the outlines of a bear cautiously emerging from cover. It sniffs the air carefully and makes its way to the pit. Soon it is snuffling around the maggoty pig. The evening light forms a halo of silver around its head. Then it grabs a limb and starts tearing flesh from the carcass. Any passing likeness to Winnie the Pooh is swiftly dispelled.

During the night two more bears swing by and, at about 3.40am, we are rewarded with a lone wolverine raiding Eero's larder. It disappears inside a tree trunk and emerges with fangs clamped on a large hunk of meat. The wolverine is businesslike and urgent, and makes a swift exit up the hillside to our left to the accompaniment of camera shutters clacking furiously.

The last great wilderness in Europe has shared a few of its secrets.

Compact Facts

How to get there

Finnair ( flies from Heathrow and Manchester to Joensuu (gateway to Karelia), via Helsinki, in August from £217 return. A weeks' car rental (Ford Focus) costs from €480 (£423): Valamo Monastery has double rooms from €110 (£97) with breakfast. The Sokos Hotel Koli has doubles from €99 (£87) with breakfast. For bookings go to:

Further information

Sankha Guha travelled as a guest of VisitFinland (