ARENDAL, a seaport of southern Norway, in Aust-Agder hike (county), at the mouth of the river Nid, 46m. N.E. of Christiansand. Estimated pop. (1930) 10,403. It has a good harbour protected from the open waters of the Skagerrak by a series of islands, on some of which the town itself, founded in 1723, is built. At one time (1879) Arendal was second only to Oslo (then Christiania) as a ship-owning port, but it lagged behind when steam-boats replaced sailing vessels, and now ranks about tenth among Norwegian ports. It is a port of call for many steamship lines. The chief exports are timber, wood-pulp, aluminium, ferro-alloys, quartz and felspar. There are two smelting works in the neighbourhood (at Eydehavn) and quarries, sawmills, a wood-pulp factory and a shipbuilding yard. The vi cinity is remarkable for its variety of minerals. A railway runs to Treitsund in Telemark.