The former Van Nelle Factory (Van Nellefabriek) is considered a prime example of the International Style and Constructivism. It has been a designated World Heritage Site since 2014.
The buildings were designed by architect Leendert van der Vlugt from the Brinkman & Van der Vlugt office in cooperation with civil engineer J.G. Wiebenga, at that time a specialist for constructions in reinforced concrete, and built between 1925 and 1931. It is an example of Nieuwe Bouwen, modern architecture in the Netherlands. It was commissioned by the co-owner of the Van Nelle company, Kees van der Leeuw, on behalf of the owners. Kees van der Leeuw and both company-directors, Matthijs de Bruyn and Bertus Sonneveld, were so impressed by the skills of Van der Vlugt that they commissioned him to design and build private houses for themselves in Rotterdam and nearby Schiedam between 1928 and 1932. The fully renovated Sonneveld House is now a museum in the centre of Rotterdam, with more than 30.000 annual visitors from all over the world.
In the 20th century it was a factory, processing coffee, tea and tobacco and later on additional chewing gum, cigarettes, instant pudding and rice. The operation stopped in 1996. Currently it houses a wide variety of new media and design companies. Some of the areas are used for meetings, conventions and events.
The Van Nelle Factory shows the influence of Russian Constructivism. Mart Stam, who worked during 1926 as employee-designer at the Brinkman & Van der Vlugt office in Rotterdam, came in contact with the Russian Avant-Garde in 1922 in Berlin. In 1926 Mart Stam organized an architecture tour of the Netherlands for the Russian artist El Lissitzky and his wife Sophie Küppers, collector of avant-garde art. They visited Jacobus Oud, Cornelis van Eesteren, Gerrit Rietveld, and other artists.References:
The Petersberg Citadel is one of the largest extant early-modern citadels in Europe and covers the whole north-western part of the Erfurt city centre. It was built after 1665 on Petersberg hill and was in military use until 1963. It dates from a time when Erfurt was ruled by the Electors of Mainz and is a unique example of the European style of fortress construction. Beneath the citadel is an underground maze of passageways that can be visited on guided tours organised by Erfurt Tourist Office.
The citadel was originally built on the site of a medieval Benedictine Monastery and the earliest parts of the complex date from the 12th century. Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site.