My comparative outlook in this paper is related to a specific category of combined museums and cultural heritage monuments; a rather small group of manor houses; mansions; villas and residences in urban and rural environments. The majority can be dated back to between 1665 and 1850. Some were protected as monuments and museums in the early twentieth century; however the majority were institutionalised during the period 1950-1990 and function today as historic houses; museums and even national monuments. Early nineteenth century political incidents gave rise to a romantic cultural movement as Norwegians sought to define and express a distinct national character. It was as a result of this movement the long union period with Denmark was referred to as ‚Äúthe Danish era‚ÄĚ or ‚Äúthe 400-year night‚ÄĚ. Collection of immaterial and material cultural heritage was followed by academic work; and folk tradition was mediated in new ways and with new explanations; contributing to the notion of nationality. Museums were important institutions in the nation-building; as vehicles for the encouraging of national values and identity in the aftermath of 1814. Institutions like the National museum for art; architecture and design; The Norwegian Museum of Cultural history and The Museum of Cultural History lead the way. How might the study of the noble and elegant; but disregarded group of mansions and manor houses contribute to the lager picture and understanding of national museums; or rather the decentralised Norwegian national museum structure? There are more reasons: Historically they belong to the last centuries of the union with Denmark; and many were protected when the opinions towards the ‚Äú400 years night‚ÄĚ were at their strongest. This makes them particularly interesting from a cultural history perspective. Secondly; some of them are among the exclusive group of national heritage monuments; and thirdly ‚Äď in a subtle way the majority seems to have close connections to the ramification of the folk- and open-air oriented museum movement and its strong national overtones.