Arendal is the biggest city in Aust-Agder, Norway with a population of around 40.000.
The administrative centre of the municipality is the city of Arendal (which is also the seat of Aust-Agder county). Some of the notable villages in Arendal include Rykene, Eydehavn, Færvik, Strengereid, Kongshavn, Kilsund, Brattekleiv, Longum, Saltrød, Staubø, Vrengen, and Kolbjørnsvik. The offices of UNEP/GRID-Arendal are also located in the city of Arendal. The 270-square-kilometre (100 sq mi) municipality is the 288th largest by area out of the 422 municipalities in Norway. Arendal is the 20th most populous municipality in Norway with a population of 44 800. The municipality's population density is 174. 7 inhabitants per square kilometre (452/sq mi) and its population has increased by 11. 3% over the last decade. The town of Arendal was established as a municipality on 1 January 1838 (see formannskapsdistrikt). On 1 January 1875, a small area with 22 inhabitants was transferred from the town to the neighboring municipality of Østre Moland and another small area with 52 residents was transferred to the neighboring municipality of Øyestad. On 1 January 1902, the rural municipality of Barbu (population: 6,787) was merged into the town of Arendal.