Naissaari’s history goes back to the beginning of the 19th century when Haapakoski’s lumber mill was founded and the island was populated with the workers of the mill. During that time the island actually was the center of the Haapakoski (nowadays Vaajakoski) region and addition to the houses of the workers and the industrial buildings there were also some shops, a post office and a school.
Before the Vaajakoski’s canal that we see today there was a smaller canal next to the island that was made to ease up timber rafting and boating. The old canal or stream was called Vaajantaipale, Kissakanava and Kissakoski and it was dammed when the construction of the power plant began.
Between 1876 and 1916 a man called James Salvesen helped to grow and thrive the area a lot. However, during 1916 he sold the majority of his holdings of the area to SOK (a Finnish retailing cooperative organisation) which almost completely rebuilt the area in the 1930s. The construction of the new canal began in 1989.