Haderslev Museum was established in 1887.
Today, it is the archaeological department of the Museum Sønderjylland that conducts excavations and controls monuments of the past across all of Sønderjylland.
The department is located in a building from 1977, which displays extensive exhibitions about prehistoric and medieval Sønderjylland.
Among other things, the exhibition contains Denmark's oldest grave, magnificent finds from the Stone Age and Bronze Age, a large exhibition about Iron Age society, including the extensive weapon offering relics from Ejsbøl, along with items from the castle mounds of Nørrevold and remains of Hansborg Castle in Haderslev.
Historical time is represented through exhibitions of town home interiors, a painter's workshop, a shoemaker's shop and a merchant's shop.
On the museum grounds is one of the country's oldest open-air museums featuring two farmhouses from the eighteenth century, a log barn from 1628, a post mill from 1741 and a smithy from the 1850s along with a series of reconstructed monuments of the past.
In the museum's back garden is one of the few preserved bronze statues of the German emperor Wilhelm I. The statue was situated on the town square in Haderslev from 1890 to 1920.