Luonnonmaa is an island in the city of Naantali

Naantali

Naantali is a city in south-western Finland, known as one of the most important tourist centres of the country. The municipality has a population of , and is located in the region of Finland Proper, west of Turku....

, in south-western Finland

Finland

Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

. It forms most of the city's area

Area

Area is a quantity that expresses the extent of a two-dimensional surface or shape in the plane. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat...

, but only a fraction of its population

Population

A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...

 as it is rather sparsely populated. It previously belonged to the rural municipality of Naantali

Naantalin maalaiskunta

Naantalin maalaiskunta , or the rural municipality of Naantali, as distinct from the city of Naantali, is a former municipality in Finland. The municipality was located in south-western Finland, surrounding the city of Naantali, and composed of rural and suburban areas around it, mostly on the...

 (Naantalin maalaiskunta), but the municipality was annexed to the city of Naantali in 1964. The island hosts the Kultaranta Castle, the official summer residence of the Finnish President of the Republic

President of Finland

The President of the Republic of Finland is the nation's head of state. Under the Finnish constitution, executive power is vested in the President and the government, with the President possessing extensive powers. The President is elected directly by the people of Finland for a term of six years....

.