CHRISTIANSAND, a fortified seaport of Norway, the chief town of the diocese (stilt) of Agder on a fjord of the Skager rack, 175 m. S.W. of Oslo (Christiania). Pop. (1930) 18,700. It stands on a square peninsula flanked by the western and eastern harbours and by the Otter river, among wooded hills and islands. It is a fishing centre (salmon, mackerel, lobsters), with sawmills, wood-pulp factories, shipbuilding yards and mechanical work shops. The port is the largest on the south coast; coast and foreign steamers on the way to Christiania touch here. The Saetersdal railway follows that valley north to Byglandsfjord (48 m.), whence a good road continues to Viken i Valle at the head of the valley. Flekkero, a neighbouring island, is a favourite pleasure resort. The town was founded in 1641 by Christian IV.