Arendal, town and port, southern Norway. Its excellent harbour is on Tromøy Sound, a protected sound sheltered by the offshore island of Tromøy. A port since the 14th century, Arendal had the largest fleet in Norway before the steamship era. From the 16th century it prospered from timber exports. Some timber is still floated down the Nidelva River, which empties into the Skagerrak (strait between Norway and Denmark) at Arendal. Besides sawmilling, the town’s chief industries include metal processing and fabricating (particularly electrical appliances) and food and tobacco processing. Arendal is one of the most important coastal shipping centres of Norway and is the terminus of a branch of the Sørland (Oslo-Stavanger) rail line. The four-story town hall is one of the largest wooden buildings in Norway. The historic battery, overlooking the harbour, was used during the war that forced Denmark to cede Norway to Sweden (1814). Pop. (2007 est.) mun., 40,057.