An unusual piece of Olympic history is to be protected for future generations.

Tucked away in the grounds of Cobdown House, in Ditton, is a modest prefabricated wooden hut which was Finland’s contribution to the 1948 Olympic Games – a sauna.

Historic England has agreed to formally list the building as being of historic importance after a campaign that involved Chatham and Aylesford MP Tracey Crouch, the Finnish ambassador Jukka Siukosaari, the Cobdown Sauna Club and others.

The building was a gift to the Games by a Finnish company called Puutalo Oy, which specialised in prefabricated buildings. It donated the sauna to the “austerity games” to help the athletes relax.

Coming just after the war, the 1948 Olympic Games were run on a shoe-string in a London devastated by German bombing.

The hut is believed to be the oldest surviving sauna in Britain.

It was initially sited in Richmond Park.

The simple building was designed by one of Finland’s top architects – Tolvo Jantti – who had earlier helped design the Helsinki Stadium intended for the 1940 Olympic Games, which were unfortunately cancelled because of the Second World War.

The hut comprises an entrance hall with a single-cubicle toilet and a small kitchen. There is a changing room – with hooks for 40 people – and a massage parlour with two massage tables.

To the right is the shower room, with one hot and one cold shower and a foot bath.

Off the shower room is the sauna cabin itself, with four rows of benches that could easily take 10 people, with the heat produced from the sauna oven which burnt birch logs.

Outside the building is a plaque commemorating the sauna’s Olympic origins.

In the 1940s, the Albert Reed Paper Mill based at Aylesford had an extensive staff sports and social club at Cobdown, and also had close connections to Finland as it was a major importer of their timber.

Its bosses invited the Finnish athletes to train at the Ditton sports fields ahead of the Games.

Afterward, the grateful Finns donated the sauna to Albert Reed for use by members of its social club.

An article in the Sport and Country magazine from 1954 shows it being used by Reed’s staff.

Later the cabin became the property of the Cobdown Sports Club – now K Sports – where it continued to be used by members of the Cobdown Sauna Club.

It closed in 2020 due to faulty electrics and a broken sauna oven and since then both Cobdown House and the sauna hut have been purchased by the payroll and HR company Advo.

Tom Foxall, the regional director at Historic England, said: “The Cobdown Sauna is a remarkable survival and would still be easily recognised by the Finnish Olympic team from 1948, as well as by the first paper mill employees lucky enough to have this novel sauna experience available to them.”

Richard Young of the Cobdown Sauna Club said: “I am so pleased. This Grade II-listing should keep it safe for future generations.

“Now we can now go forward and get the sauna working again for our members.”

Ambassador Siukosaari said: “This is excellent news, not only because of the building’s unique architecture, but also because of its significance to Finnish-British relations and our common sporting history.

“Preserving it will guarantee that future generations in the UK will get to learn about sauna as an institution and its significance to the Finnish culture.

“I especially want to thank the local community in Aylesford, who have looked after this special building for so many years.”

Tracey Crouch MP said: “I am absolutely delighted.

“The sauna, with its connection to sport and our now-gone paper mills, is to have its heritage protected by this listing, giving local people the opportunity to stay connected to an industry that is sadly no more, via this wonderful gift from the 1948 Finnish Olympic team.”

It is hoped that a listed status might help release grants to restore the sauna to full working order.