Southwest Friesland is a municipality in the northern Netherlands, located in the province of Friesland. It had a population of 89,999 in January 2…Southwest Friesland is a municipality in the northern Netherlands, located in the province of Friesland. It had a population of 89,999 in January 2021. Sneek is the municipal seat. With a total area of 841.56 km, Southwest-Friesland is the largest municipality by area in the Netherlands.