the 20th century. Many historical buildings were torn down during the modernist era, including substantial parts of the historical district of Klara, and replaced with modern architecture. However, in many other parts of Stockholm (such as in Gamla stan, Södermalm, Östermalm, Kungsholmen and Vasastan), many "old" buildings, blocks and streets built before the modernism and functionalism movements took off in Sweden (around 1930–35) survived this era of demolition. Throughout the century, many industries shifted away from industrial activities into more high-tech and service industry areas. Stockholm's metropolitan area is one of the fastest-growing regions in Europe, and its population is expected to number 2.5 million by 2024. In 2020 alone, Stockholm's population increased by 1,477. As a result of this massive population growth, there has been a proposal to build densely packed high-rise buildings in the city centre connected by elevated walkways. Geography Location Stockholm is located on Sweden's east coast, where the freshwater Lake Mälaren — Sweden's third-largest lake — flows out into the Baltic Sea. The central parts of the city consist of fourteen islands that are continuous with the Stockholm archipelago. The geographical city centre is situated on the water, in Riddarfjärden bay. Over 30% of the city area is made up of waterways and another 30% is made up of parks and green spaces. Positioned at the eastern end of the Central Swedish lowland, the city's location reflects the early orientation of Swedish trade toward the Baltic region. Stockholm belongs to the Temperate deciduous forest biome, which means the climate is very similar to that of the far northeastern area of the United States and coastal Nova Scotia in Canada. The average annual temperature is . The average rainfall is per year. The deciduous forest has four distinct seasons, spring, summer, autumn, and winter. In the autumn the leaves change color. During the winter months, the trees lose their leaves. For details about the other municipalities in the Stockholm area, see the pertinent articles. North of Stockholm Municipality: Järfälla, Solna, Täby, Sollentuna, Lidingö, Upplands Väsby, Österåker, Sigtuna, Sundbyberg, Danderyd, Vallentuna, Ekerö, Upplands-Bro, Vaxholm, and Norrtälje. South of Stockholm: Huddinge, Nacka, Botkyrka, Haninge, Tyresö, Värmdö, Södertälje, Salem, Nykvarn and Nynäshamn. Stockholm Municipality Stockholm Municipality is an administrative unit defined by geographical borders. The semi-official name for the municipality is City of Stockholm (Stockholms stad in Swedish). As a municipality, the City of Stockholm is subdivided into district