Ruairi O'Brien's Plattenbau Museum in Dresden, featured at project stage in AJ 17.7.03, is now open, though it will continue to develop, writes Andrew Mead. Conceived as an unusual fusion of museum and landscape architecture, it is on the edge of a site formerly occupied by a factory that made the concrete slabs and cladding for plattenbau - the prefabricated buildings that were such a staple of the former East Germany. The visitors' path zigzags between triangular containers in which samples of the factory's evolving products are displayed chronologically. In the distance are some still surviving plattenbau, making a 'micro-macro' connection between the evocative fragments in the museum and the huge housing schemes that they served. The 'timeline' path leads to a door in a ruined silo with a lightwork above it, which says Betreten auf eigene gefahr (Enter at your own risk); and beyond is the Einheitsgarten (the garden of unification), illuminated at night. O'Brien realised the scheme on a minimal budget with the help of unemployed building workers and local residents.