La Seu d'Urgell is a town located in Alt Urgell county in Alt Pirineu, Catalonia, Spain. The town is also the head of its judicial district and the seat of the Bishop of Urgell, one of the co-princes of Andorra. It is located the most populated town of the region, with 17.4% of its population. La Seu d'Urgell and Puigcerdà together have 30% of the population of the area. It is located at the confluence of the Segre and the Valira rivers.