The Vefsn Museum is split over two sites. In Sjøgata, the Jakobsensbrygga Warehouse is an excellent small museum that portrays, via some particularly evocative photo enlargements, the history of Mosjøen from the early 19th century onwards. Northeast of the centre, the rural building collection features 12 farmhouses, shops and the like from the 18th and 19th centuries, which you can view from the exterior. Both have helpful pamphlet guides in English.
Adjacent to the building collection is the Dolstad Kirke (1735), built on the site of a medieval church dedicated to St Michael. A combined ticket gives entry to both branches of Mosjøen's museum.