Sils is a municipality in the comarca of Selva, in Catalonia, Spain. It is situated next to a former lake, which was drained in the nineteenth ce…Sils is a municipality in the comarca of Selva, in Catalonia, Spain. It is situated next to a former lake, which was drained in the nineteenth century. Autopista AP-7 and road N-II run through the municipality, and there is a Renfe railway station on the line between Barcelona and Girona.