Denmark, constitutional monarchy, north-western Europe, the southernmost of the Scandinavian countries. Officially the Kingdom of Denmark ,it is bordered on the north by the Skagerrak, an arm of the North Sea; on the east by the Kattegatt and the Øresund ,a strait linking the Kattegatt and the Baltic Sea; on the south by the Baltic Sea, the Fehmarn strait, and Schleswig-Holstein, Germany; and on the west by the North Sea. Denmark comprises most of the Jutland, or Jylland, peninsula (extending about 338 km/210 mi in a north and south direction), and more than 400 islands in the Baltic and North seas. About 130 km (80 mi) to the east of Sjaelland, in the Baltic, is the Danish island of Bornholm.