Linnanmäki (, colloquially Lintsi, ) is an amusement park in Helsinki, Finland. It was opened on 27 May 1950 and is owned by the non-profit Children's Day Foundation (, ), which operates the park in order to raise funds for Finnish child welfare work. In 2019, the foundation donated , and so far has donated a total of over to this cause. Linnanmäki is the oldest and most popular amusement park in Finland. It has many rides of different types and sizes, and of the all Nordic amusement parks, Linnanmäki has the most rides in relation to the number of visitors. It also has other attractions, including arcades, games, kiosks, restaurants and an outdoor stage on which different performers appear in the summer. The park is open from spring to autumn and is visited by over a million guests annually. In August 2006, Linnanmäki received its fifty-millionth visitor. History In 1950, six Finnish child welfare organisations leased an area from the city of Helsinki for an initial period of three years in the middle of a recreational area consisting of two parks, where they set up an amusement park. The city extended the lease in 1953 and leased for the amusement park. In accordance with the city plan approved in 1956, the amusement park area was expanded to more than . In 1957, the welfare organisations established the non-profit Children's Day Foundation, which continues to maintain and develop the amusement park. Today, the site covers . Linnanmäki is built on a hill and derives its name from Vesilinnanmäki (), the name locals gave to the hilly area in the early 20th century since it had two water towers, built in 1876 and 1938, respectively. The water towers are no longer in operation and were disconnected from the grid in 2003. However, the towers are protected by the zoning plan of the city and cannot be demolished. In the future, it is hoped that the towers will be used year-round to support amusement park activities. The older, angular tower near the perimeter of the amusement park—the oldest water tower in Helsinki—currently houses the park's maintenance and storage facilities, while the newer, cylindrical tower dominating the park and its wider surroundings houses an indoor roller coaster called Linnunrata eXtra. Since its opening in 1950, two people have died in amusement ride accidents at Linnanmäki, both caused by negligence on the part of