Compostela is the name of both a municipality and of a town in it that serves as the seat; both are in the Mexican state of Nayarit. The mun…Compostela is the name of both a municipality and of a town in it that serves as the seat; both are in the Mexican state of Nayarit. The municipality had 62,925 in a total area of 1,848 km. The town and its municipal seat had a population of 15,991 in 2000.