CARLSBURG, a fortified town of Transylvania, capita] of the county of Unter-Weissenburg, situated on the north bank of the Maros, 54 miles south of Clausenburg. It consists of the upper town, or citadel, and the lower town. It has a fine Roman Catholic cathedral (containing among other tombs that of John Hunniades), Lutheran and Reformed churches, and a synagogue; also an ecclesiastical seminary, gymnasium, observatory, public library, mint, &c. Population in 1874, 7955. Lat. 46° 4' 17" N., long. 23° 34' E.