The Kostomuksha construction project brought thousands of Finnish workers into the Soviet Union between 1977 and 1985 to build a mining town and iron pellet plant close to Finland’s eastern border. For those involved, the vast site combined professional ambition, economic opportunity and the closely controlled atmosphere of the Cold War.
Kostomuksha, known as Kostamus in Finnish, lies in Russian Karelia about 40 kilometres from the Finnish border, directly east of the Kainuu region. Finland and the Soviet Union agreed to construct the town and industrial complex as part of their extensive bilateral trade relationship.
At its peak in 1978, the site employed 3,147 Finnish workers, according to Yle. More than 60 percent came from Kainuu, where unemployment had been rising and construction jobs were scarce. Over eight years, the project generated approximately 16,000 person-years of employment for Finnish workers.
The Kostomuksha construction project was built on an exceptional scale
The Finnish contract covered around 550 separate construction sites, including industrial buildings, apartment blocks, shops, kindergartens and a cultural centre. Finnish companies built the structures, while Soviet workers installed the industrial machinery.
The main contractor was Finn-Stroi, a consortium formed by several of Finland’s largest construction companies. The project followed Finnish involvement in the construction of the Svetogorsk pulp and paper complex, another major industrial development across the Soviet border.
Aulis Jurvansuu arrived in Kostomuksha in 1978 as a 24-year-old construction supervisor. He initially managed surveying teams and later became a concrete supervisor, overseeing technically demanding work such as the continuous casting of the pellet plant’s 180-metre chimneys.
Jurvansuu described the site to Yle as a “university of construction technology”. The scale of the work was difficult to reproduce in Finland. He recalled that Kostomuksha had what was believed to be Europe’s largest concrete mixing plant at the time.
“In Kostomuksha, there was little discussion about how much something would cost or whether the company had enough money,” he said. “I only encountered that kind of discussion when I continued working in construction in Finland.”
A Finnish community inside the Soviet Union
The Finnish workforce lived in an environment largely separated from the surrounding Soviet community. Workers had access to their own banks, postal services, shops, canteens, healthcare facilities and organised leisure activities.
Accommodation operated by Finn-Stroi included room cleaning, bed-making and regular changes of linen. Workers initially lived in temporary barracks before moving into apartment buildings they had helped construct.
A previous Yle account of the project described the Finnish compound as almost “a state within a state”. Contact with Soviet citizens was officially restricted, while border checks, passports and access permits remained a visible part of everyday life.
Coffee, jeans and tights were nevertheless exchanged informally with local residents for roubles or vodka. Cheap alcohol and card games became part of life in some shared accommodation, although Jurvansuu rejected the idea that they defined the project.
“A construction site that large could not have been completed by drinking,” he told Yle.
Work, relationships and the risks of the site
Finnish workers received salaries comparable to those paid for similar jobs at home. Tax-free daily allowances made employment across the border financially attractive, allowing some workers to accumulate substantial savings.
Only around 10 percent of the workforce were women. One of them was Riitta Piirainen, who arrived as an occupational health nurse in late 1980 after struggling to find work in Helsinki.
She met Aulis Jurvansuu at a social evening three months later. The couple married in 1983, which allowed them to obtain family accommodation in Kostomuksha. They later used their savings from the project to build a cottage in Sotkamo without taking out a bank loan.
The vast construction site also carried serious risks. Riitta Jurvansuu was once called to an accident at the pellet plant after a crane load struck a 50-metre metal column, causing vibrations across the structure. Two concrete slabs weighing approximately 3,000 kilograms began to slide. One worker fell with a slab and died.
Despite the fatal accident, the couple recalled that occupational safety representatives regularly inspected the site and intervened when they found problems.
Life inside a Cold War bubble
Crossing the Finnish-Soviet border remained a powerful reminder of the political environment surrounding the project. Guards searched bags and inspected vehicles, while checks of passports and access permits could take several hours.
Workers generally spent weekdays in Kostomuksha and returned to Finland at weekends. The arrangement offered professional experience and steady income, but it also created a sense of isolation.
“I had the feeling that life existed only during the weekend,” Riitta Jurvansuu said. “In Kostomuksha, we were as if inside a tin can.”
The project ended in 1985, becoming one of the largest Finnish construction export operations of the post-war period. The mining town and industrial complex remain physical evidence of an era when Finland maintained extensive economic cooperation with the Soviet Union while remaining outside the Eastern Bloc.
A documentary is seeking the remaining stories
Finnish documentary director Markku Heikkinen, who spent his childhood and youth in Kainuu, is now conducting background research for a film about the people who built Kostomuksha.
Many of the youngest Finnish workers involved have already retired or are approaching retirement age. Heikkinen wants to record their experiences while first-hand testimony is still available.
The project has received a grant for preliminary research, but its production schedule remains uncertain because further financing is required. Heikkinen hopes filming can begin in 2027 and is looking for a family whose history connects the Kostomuksha project with life along Finland’s eastern border.
The planned documentary could preserve more than memories of an unusual construction site. It may also show how employment, personal relationships and Cold War politics intersected in a Finnish community that lived only a few kilometres from home, but on the other side of one of Europe’s most closely controlled borders.
