La Unión is a city and commune of the Ranco Province in the Los Ríos Region in Chile. It is situated approximately 40 km north of Osorno a…La Unión is a city and commune of the Ranco Province in the Los Ríos Region in Chile. It is situated approximately 40 km north of Osorno and 80 km southeast of Valdivia. Covering an area of 2,136.7 km, it has a population of 36,447, of which 25,615 are considered part of the urban population, according to the 2012 census. The commune derived its name from the confluence of the Llollelhue and Radimadi rivers.