Lahnus
{{Infobox settlement
| name = {{lang|fi|Lahnus}}
| native_name =
| native_name_lang = sv
| settlement_type = District of Espoo
| image_skyline = Serenan ulkoallas panorama.jpg
| image_alt =
| image_caption = Serena Waterpark in Lahnus
| image_map = Espoo districts Lahnus.png
| map_alt =
| map_caption = Location of Lahnus within Espoo
| pushpin_map =
| pushpin_map_caption = Location of Lahnus within Finland
| coordinates =
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| subdivision_type = Country
| subdivision_name = Finland
| subdivision_type1 = Municipality
| subdivision_name1 = Espoo
| subdivision_type2 = Region
| subdivision_name2 = Uusimaa
| subdivision_type3 = Sub-region
| subdivision_name3 = Greater Helsinki
| subdivision_type4 = Main District
| subdivision_name4 = Pohjois-Espoo
| subdivision_type5 = Inner District(s)
| subdivision_name5 = Lahnus
| established_title =
| established_date =
| leader_title =
| leader_name =
| area_footnotes =
| area_total_km2 =
| area_land_km2 =
| area_water_km2 =
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| population_footnotes =
| population_total = 762
| population_as_of = 2006
| population_density_km2 = auto
| demographics_type1 = Languages
| demographics1_footnotes =
| demographics1_title1 = Finnish
| demographics1_info1 = 93.6 %
| demographics1_title2 = Swedish
| demographics1_info2 = 5.2 %
| demographics1_title3 = Other
| demographics1_info3 = 1.2 %
|blank_name_sec1 = Jobs
| blank_info_sec1 =
| website =
}}
Lahnus is a district in the city of Espoo and administratively belongs to the Northern Espoo area. It is located near the municipality of Nurmijärvi and its largest village, Klaukkala. The most famous places in Lahnus are the Serena Waterpark{{cite web|url=https://www.serena.fi/en/|title=Serena - Home|accessdate=August 14, 2019}} and Hotel Korpilampi.{{cite web|url=https://www.korpilampi.fi/en/|title=Hotel Korpilampi - Home|accessdate=August 14, 2019}}
Finnish regional road 120 (Vihdintie) between Helsinki and Vihti, one of the most important road connections from Lahnus to the capital, passes through the district.{{cite web|url=https://vayla.fi/uudellamaalla-rakenteilla/mt-120-lahnuksen-liittyman-parantaminen|title=Vihdintien, Lahnuksentien ja Vanhan Lahnuksentien liittymä, Espoo|publisher=Väylä|access-date=March 12, 2020|language=fi}} Along the road, at the intersection near the Shell filling station, the north branch road to Klaukkala is Lahnuksentie (Mt 1324).{{cite web|url=https://www.espoo.fi/fi-FI/Asuminen_ja_ymparisto/Kadut_ja_liikenne/Liikennesuunnittelu/Liikennehankkeet/Ajankohtaiset_hankkeet/Lahnuksentie/Maantien_1324_Lahnuksentie_vali_LahnusKl(153553)|title=Maantien 1324 Lahnuksentie, väli Lahnus-Klaukkala, esisuunnitelman laatiminen jalankulku- ja pyöräilyväylästä|publisher=Espoon kaupunki|access-date=March 12, 2020|language=fi}} There are also several nature reserves in Lahnus: Tremanskärr Nature Reserve and Luukki Nature Reserve, as well as part of Nuuksio National Park.
Lahnus is an old village name and has been spelled, among others: Lanoxby (1540), Lanos (1541), Lanas (1547), Lora (1558), Loureby (1559), Lahcnus (1563) and Lahnås (1594).{{cite web|url=https://www.espoo.fi/fi-FI/Asuminen_ja_ymparisto/Kaavoitus/Nimisto/Nakokulmia_nimistoon/Lahnus(98052)|title=Espoo - Lahnus|accessdate=September 14, 2019|language=fi}} The name is probably of Finnish origin, but the meaning is unclear.{{cite web|url=http://www.espoo.fi/default.asp?path=1;28;11866;17468;17633;17653;17715;17716|title=Esbo stadsdelsnamn|accessdate=August 14, 2019|language=sv|archive-url=https://web.archive.org/web/20070930224804/http://www.espoo.fi/default.asp?path=1%3B28%3B11866%3B17468%3B17633%3B17653%3B17715%3B17716|archive-date=September 30, 2007|url-status=dead}} The highest daily rainfall in Finland was measured in Lahnus: on July 21, 1944, it was 198 millimeters.{{cite web|url=http://ilmatieteenlaitos.fi/sade-ennatyksia|title=Sade-ennätyksiä - Ilmatieteen laitos|publisher=ilmatieteenlaitos.fi|accessdate=August 14, 2019|language=fi}}