This lakeside amusement park was built around an aquarium, planetarium, and observation tower complex.  Its first amusement rides, including a wooden wild mouse, operated in 1973 and 1974 and were owned by Finnish showmen.  In the year 1975, the management of the park was given to the Lasten Päivä-foundation, which owns Linnanmäki.  Several rides were moved from Linnanmäki to Särkänniemi, but when their cooperation ended in the year 1984, those rides were moved to Tykkimäki, another park owned by the foundation.  The observation tower, Näsinneula, along with other original attractions, are still in use, along with many new attractions that have been added over the years.

Official Site: link