Serón adds the name of its river Historical milestone · Serón de Nágima, Las Vicarías, Soria Image of Serón de Nágima, not of the place itself. Known as Serón since the twelfth century, when it was a frontier stronghold between Castile and Aragon, in 1916 the town added to its name that of the river that crosses it and came to be officially called Serón de Nágima. 1916 Photo: Dgarcia29 Esta foto esta realizada por mi y la cedo a wikipedia. (Public domain) What to see and do in Serón de Nágima