Porrentruy District is one of the three districts of the canton of Jura, Switzerland. Its capital is the town of Porrentruy. The French-speakin…Porrentruy District is one of the three districts of the canton of Jura, Switzerland. Its capital is the town of Porrentruy. The French-speaking district has a population of 24,276. The blazon of the district coat of arms is Gules a Fess Argent, overall a Cockatrice Or volant holding in legs and beak a Crosier of the same.