Kouvola (ˈkou̯ʋolɑ) is a city and municipality in southeastern Finland. It is located along the Kymijoki River in the region of Kymenlaakso, kilometers east of Lahti, west of Lappeenranta and northeast of the capital, Helsinki. With Kotka, Kouvola is one of the capital centers and is the largest city in the Kymenlaakso region. The whole municipal area has a population of (), but the actual downtown itself is home to 47,391 people. It covers an area of of which is water. The population density is . Kouvola is bordered by the municipalities of Hamina, Heinola, Iitti, Kotka, Lapinjärvi, Loviisa, Luumäki, Miehikkälä, Mäntyharju, Pyhtää and Savitaipale. Kouvola has over 450 lakes and, together with Mäntyharju, the Kouvola area includes the Repovesi National Park. Kouvola, which had population growth as late as the 1980s, has suffered a loss of migration since the 1990s. Over time, the loss has only deepened, so that at the end of the 2010s Kouvola was Finland's worst migration loss area. Natural demographics have also trended downward; in 2017, more than 450 more people died in the city than new ones were born. The reasons for the emigration are thought to be largely due to job losses in the region. The village of Kouvola has been inhabited since the Middle Ages, and it has belonged alternately to the churches of Hollola, Iitti and Valkeala. However, the actual development did not start until the 1870s when the Riihimäki–Saint Petersburg line was built and Kouvola became a railway junction. Kouvola railroad built Kymin mill founder Axel Wilhelm Wahren railway administration by on application, on the basis of the track engineers decided to recommend the creation of a fifth-end position in a half mile east of the variable alert Otava with acceptance on sandy soil on fabric. In the next decade, the Savonia railway was built from Kouvola to the north and the Kotka line to the south, resulting in Kouvola becoming one of the busiest railway junctions in Finland.