KULMSEE, a town of Germany, in the Prussian province of West Prussia, on a lake, 14 m. by rail N. of Thorn and at the junction of railways to Bromberg and Marienburg. Pop. (1900), 8987. It has a fine Roman Catholic cathedral, which was built in the 13th, and restored in the 15th century, and an Evangelical church. Until 1823 the town was the seat of the bishops of Kulm.