The municipality of Seia is situated in the Center region, on the northwestern slope of Serra da Estrela Natural Park (26% of the area). Administratively, the municipality is divided into 21 civil parishes. Seia was elevated to city status on July 3, 1986.
The population in 2019 was 22577, in an area of 435.69 km2. The number of families in the municipality of Seia is around 9500, with a fertility index of 1.22, with an average family size of 2,5 and an aging rate of 278.9%.
The Municipality of Seia is part of the Intermunicipal Community of Beiras and Serra da Estrela, and Seia is the second largest city in the Serra da Estrela sub- region and the second largest city in Guarda District.
