Situated adjacent to the New Town Hall, the museum comprises the state gallery (Landesgalerie), featuring paintings and sculptures from the Middle Ages to the 20th century, and departments of archaeology, natural history and ethnology.

The museum soon ran out of space for its art collections, prompting the construction of the current building, designed by Hubert Stier in a Neo-Renaissance style,[2] on the edge of the Maschpark in 1902.

The department also has zoological, botanical, anthropological, geographical and geological exhibits on the primeval history of Lower Saxony's regions, including the Harz mountains, the heathlands, and the North Sea coast.

[4] The archaeology department is supported by the Lower Saxon State Society of Prehistory (Niedersächsischer Landesverein für Urgeschichte), and its working group Arbeitskreis...

[5][6] The ethnological collection is among the oldest in the German-speaking area of Europe (Deutscher Sprachraum), and includes around 20,000 artworks and everyday artefacts from all parts of the world.

The museum regularly hosts temporary exhibitions on changing themes, and its pest control facility (a nitrogen chamber) suitable for artworks and artefacts is available for use by the public.