Mustikkamaa

Mustikkamaa (Finnish: [ˈmustikːɑˌmɑː]; Swedish: Blåbärslandet; literally translates to "blueberry land") is an island in the Gulf of Finland, some 5 kilometres (3.1 mi) to the east of the city centre of Helsinki, and c. 36 hectares (89 acres) in size.

[1] It is owned by the City of Helsinki, and used for public recreational and leisure activities such as jogging, hiking, cross-country skiing, tennis and other ballgames.

[1] In 2016, the new Isoisänsilta bridge was opened, connecting Mustikkamaa also to the Kalasatama neighbourhood on the Helsinki mainland.

[2] In the 1980s, three large rock caverns were excavated under Mustikkamaa, to store oil reserves.

In 2021, the Helsinki municipal energy company HELEN took them into use as thermal energy storage facility,[3] capable of holding 260,000 cubic metres (9,200,000 cu ft) of warm (45 °C (113 °F) or warmer) water, with the aim of reducing Helsinki's carbon emissions by over 20,000 tons annually.