Monção is a municipality in the district of Viana do Castelo in Portugal. The population in 2011 was 19,230, in an area of 211.31 km. The current …Monção is a municipality in the district of Viana do Castelo in Portugal. The population in 2011 was 19,230, in an area of 211.31 km. The current mayor is the Social Democrat António Barbosa. The municipal holiday is March 12.