Harmaja is an island and a lighthouse

Lighthouse

A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....

 outside Helsinki

Helsinki

Helsinki is the capital and largest city in Finland. It is in the region of Uusimaa, located in southern Finland, on the shore of the Gulf of Finland, an arm of the Baltic Sea. The population of the city of Helsinki is , making it by far the most populous municipality in Finland. Helsinki is...

, south of the Suomenlinna

Suomenlinna

Suomenlinna, until 1918 Viapori , or Sveaborg , is an inhabited sea fortress built on six islands , and which now forms part of the city of Helsinki, the capital of Finland.Suomenlinna is a UNESCO World Heritage site and popular with both tourists and locals, who...

 sea fortress. The island has been functioning as a landmark since the 16th century. A landmark structure was built on the island in the 18th century and a light house in 1883. The first lighthouse was only 7.3 m high and it soon proved to be too low. In 1900 the height was doubled by creating a rectangular brick building on a granite base. A large foghorn

Foghorn

A foghorn or fog signal or fog bell is a device that uses sound to warn vehicles of hazards or boats of the presence of other vehicles in foggy conditions. The term is most often used in relation to marine transport...

 alerted ships in fog and in bad visibility. Harmaja received the world's first directed and undirected radio beacon in 1936. The lighthouse is fully automated today.

There is also a pilot station on the island.

During the 1952 Summer Olympics

1952 Summer Olympics

The 1952 Summer Olympics, officially known as the Games of the XV Olympiad, were an international multi-sport event held in Helsinki, Finland in 1952. Helsinki had been earlier given the 1940 Summer Olympics, which were cancelled due to World War II...

 this was the center of the Olympic sailing event

Sailing at the 1952 Summer Olympics

Sailing/Yachting is a Olympic sport starting from the Games of the 1st Olympiad . With the exception of 1904 and possible 1916 sailing was always a part of the Olympic program....

.