The Aust-Agder Museum encompasses several collections and sites across the Arendal region, with the main building in the town centre. The collections cover maritime history, the timber trade, and the social history of coastal Agder — which is to say, the history of how this community made its living from the sea and the forests for several centuries.
The maritime collection is particularly strong, covering the age of sail when Arendal was one of Norway's largest shipping towns and its merchant fleet traded across the Baltic and the North Sea. There are ship models, navigational instruments, and documentary records of the voyages that built the town's wealth. The museum building itself, in the old town, is a fine example of the timber architecture that characterises the region.