The Museum of Knjaževac is located in Njegoševa Street 6, home of Aleksa Aca Stanojević. After the reconstruction and revitalization house was opened to the public in 1989. The house has a memorial, museum and representative function. The interior of the house consists of personal belongings of Aca Stanojević and things that belonged to Knjaževac town families. The building itself was built in the period 1910-1915 according to the architectural plan of the undertaker Fogler, an engineer from Vienna. It was built as a free facility with a rich facade plastic, with a yard, front garden and a fence, so that the external appearance gives the characteristics of Italian villas with a symmetrical facade and attractive wooden front porch with elements of Art Nouveau. The house was a gift to the city by Stanojević’s successor Branislava Marković (1903-1983).
The lower floor is a space that was previously used for a variety of programs. The first gallery in Knjaževac was opened there and was used as a salon for weddings. This part was used for organizing literary and cultural evenings, ceremonial signing of contracts and for holding lectures or conferences. After the renovation works, an opportunity was created to turn the lower floor into a part of the museum's exhibition and to connect it with the existing exhibition on the first floor. The new exhibition on the lower floor of the City Museum in the house of Aleksa Aca Stanojević is conceived on the principle of an open depot where related objects are exhibited as thematic sections with the use of modern visual and didactic material. The exhibition includes objects from the ethnological collection, collection of applied and fine arts and illustrates the private life of the town of Knjaževac from the middle of the 19th to the middle of the 20th century through the story of people who contributed to the development of the town of Knjaževac.