The Horta Museum is a museum dedicated to the life and work of the Belgian Art Nouveau architect Victor Horta and his time. The museum is housed in Horta's former house and atelier, Maison & Atelier Horta (1898), in the Brussels municipality of Saint-Gilles. In the splendid Art Nouveau interiors there is a permanent display of furniture, utensils and art objects designed by Horta and his contemporaries as well as documents related to his life and time. - in: wikipedia
When banker and art collector Adolphe Stoclet commissioned this house from one of the leading architects of the Vienna Secession movement, Josef Hoffmann, in 1905, he imposed neither aesthetic nor financial restrictions on the project. The house and garden were completed in 1911 and their austere geometry marked a turning point in Art Nouveau, foreshadowing Art Deco and the Modern Movement in architecture. Stoclet House is one of the most accomplished and homogenous buildings of the Vienna Secession, and features works by Koloman Moser and Gustav Klimt, embodying the aspiration of creating a ‘total work of art' (Gesamtkunstwerk). Bearing testimony to artistic renewal in European architecture, the house retains a high level of integrity, both externally and internally as it retains most of its original fixtures and furnishings. - in: http://whc.unesco.org/en/list/1298
The mansion is still occupied by the Stoclet family. It is therefore not open to visitors. The palace was designated as a world heritage site by UNESCO in June 2009.