The Palazzo Castelmur in Coltura near Stampa belongs to the Bregaglia municipality. In 1961, the heirs sold the Castelmur property to the community and it was turned into a museum.
The Palazzo's architecture is a hybrid of styles. When Giovanni Castelmur (1800–1871) purchased the patrician Redolfi mansion, originally built in 1723, he added a facade flanked by towers in Lombard/Venetian gothic style; this was completed in 1854. The successful combination of old and new along with the luxurious furnishings are the work of various Milanese craftsmen such as engineer and architect Giovanni Crassi-Marliani, stonemason Giovanni Pedrazzini and painter Gaspare Tirinanzi. The remaining artisans came from the neighboring Lombardy region.
The interior design of the Mansion, although more opulent, is consistent with the exterior architectural style of the building. With the exception of one room, the wood paneling in the rooms located in the original Redolfi structure, are varnished or wallpapered. In the newer part of the Mansion, there is a lovely dining room, living room, red and green wallpapered bedroom and four small tower rooms. The walls and ceilings of certain rooms are decorated with wall paintings; the trompe-l'oeil are particularly stunning.
Giovanni de Castelmur, who had been styled a Baron in France, married in 1840 his cousin Anna de Castelmur.
The Palazzo Castelmur houses Bregaglia’s historical archive (Archivio storico della Bregaglia). The archive and the Ciäsa Granda Museum belong to the Cultural Society of Bregaglia, a section of the Pro Grigioni Italiano. The goal of this documentation center is to collect and store primary sources related to local history and to make this data available to the public.
The photographic archive, with historical images of Bregaglia divided by places and themes, can be consulted online.
Palazzo Castelmur hosts a permanent exhibition on the pastry chefs from Graubünden who emigrated to many European cities to run well-known cafés and pastry shops.