Here is little more about the Villa Rauhaniemi. I found it from the web-pages of the UK embassy. I never heard that Yusupovs would have had any other property in Finland.
Villa Rauhaniemi
"The third lot of land sold was quite large and called 'Lumme', meaning water lily. It was bought by Princess Zaneida Yusupoff, a well-known celebrity in social circles and member of one of the wealthiest families in St. Petersburg. She was also a guest and shareholder of the health spa company, which raised its credibility and social significance tremendously. The villa she built was called 'Rauhaniemi' (headland of peace) and was completed in 1844. It was built directly where the British Residence now stands. There was a strong rumour circulating at the time that the Princess bought the lot because it was so near to the island of Suomenlinna – site of Helsinki's offshore naval fortress -where her lover Isakoff, a demoted captain, was billeted at the time.
A Russian architect designed the first drawings for the villa, with final construction drawings being completed by the architect A.F. Granstedt. The four-storey villa, characterised at that time as 'a monstrous extravaganza in the eastern tradition', had roof terraces and elongated arched windows. There were 15 rooms and one large salon. The rooms, adorned with chandeliers and French wallpaper, were decorated with gypsum ornamentation to almost distasteful excess. The garden housed a smaller villa, and a stable building in the neo-gothic style. This stable, containing four stalls, a carriage shed, one room downstairs and one above, still exists today at the open-air museum of Seurasaari in Western Helsinki, where it was brought in 1918.
The villa was eventually sold and changed hands several times, first to Captain Topelius in 1869, then to Consul Borgstrom in 1874. In 1878 it was sold again to the manufacturer F .W. Gronqvist and, during his ownership, the City Authorities took over the whole of Kaivopuisto, reducing the size of the lot by dissolving a third of it back into the park.
From the mid-19th century Helsinki began to attract those people interested in new business opportunities. German merchants moved from Lubeck to Finland, among them Frank Stockmann and Eduard Paulig, whose businesses are still in operation today.
In 1898 Karl Stockmann, who had married Gronqvist's daughter in 1890, moved into the house with his wife to join his father-in-law, who was by then a widower. Karl Stockmann bought the house and grounds from Gronqvist in 1908. He divided the land into three plots - now the sites of the British Embassy, the British Ambassador's Residence and the French Embassy, and built his own house, designed by Lars Sonck, on the plot now occupied by the British Embassy. "
also a little bit about the area of Kaivopuistowhere the villa was.
The development of Kaivopuisto
"The headland known as Kaivopuisto, situated to the southwest of Helsinki's central harbour, was devoid of houses and in its complete natural state up until the end of the 18th century. The higher northeastern side consisted primarily of exposed glaciated bedrock, whilst the south- west side was essentially flat, with a hill to the south and a lake in the west corner. This natural lake was popular for boating parties.
For many centuries Finland had been a part of Sweden's Eastern Province. When Finland became a Grand Duchy within the Russian Empire in 1809 it had to surrender this undeveloped coastal area, known as Ullanlinna, to the Empire's Institute of Engineering.
The Russians released the Kaivopuisto headland back to the City, however, a couple of decades later following the decline in the military strategic value of the Ullanlinna district.
After much debate the City adopted the radical decision to develop the whole headland into parkland, and lease a section of the land for the construction of a private health spa and baths. A limited company was formed for the health spa, with shares being bought, among others, by the Russian Czar, Nikolai I.
During the early 1830's the park was developed and the health spa opened to the public in 1838. There were two individual timber buildings, both designed by Carl Ludwig Engel, the architect famous for masterminding the design of Helsinki's Senate Square buildings and City Cathedral. The actual bathing rooms numbered 25 and were located in a long low building situated on the coast. A sumptuously decorated apartment was centrally located above, to house the Czar during his occasional visits.
The main building, set back in the park, was named Kaivohuone and still exists today, although it has been radically altered over the years. The original design provided for several large salons, a billiard room, restaurant and society room for ladies plus a newspaper reading room. The restaurant manager also lived on the premises.
The health spa became very popular within the higher circles of Russian society, partly because the Czar had forbidden citizens to travel outside Russian territory and partly because of its proximity to St Petersburg. The baths offered a variety of experiences from chlorinated spring water to scented water and even refreshing seawater. The main building served specially prepared mineral drinking water, which at the time was fashionable as a health cure. This water was produced and specially mixed into a variety of combinations by the then High Commissioner, Victor Hartwall. The family firm Hartwall has been Finland's leading producer of mineral water ever since.
Dancing was arranged twice weekly, Sunday being for the plutocracy, while Wednesday, was reserved for the nobility. The busiest summer recorded at the spa was in 1850 when 27,000 baths were taken.
Sadly this heyday only lasted 20 years. Two outbreaks of cholera, and the Crimean War soon after, put an end to it. The building housing the baths was finally wiped off the landscape during heavy bombing in 1944. "
