Three thematic areas consistently occupy Olafur Eliasson in his photographs and his light and object installations: the effects of thermal phenomena, the relationship between the artificial and the organic, and finally the nature of light in its various forms and qualities. In 2002, the Öffentliche Kunstsammlung Basel acquired several significant, multi-part photographic series by the artist. For example, The Cave Series, 1998, allows views into or out of caves in Iceland, and The Aerial River Series, 2000, follows the entire course of a river from its source into the as seen from the air. In the past few years these photo series have been supplemented with additional important works. It was possible to acquire one of Eliasson’s first light pieces, Infinity, 1991, with funds from the Petzold Müller-Stiftung. This piece shows a narrow blue band of light that strikes the wall horizontally the artist’s eye level. The installation Your Space Embracer, 2004, consists of a mirrored glass cylinder that slowly revolves on its own axis. The beam of a spotlight is directed at the cylinder, giving rise to a play of reflections and alternating silhouettes on the walls, ceiling, and floor. A more recent purchase, the work Sunset Series, 2006, was even more occasion to draw attention to the wide-ranging oeuvre of one of the most important contemporary artists, whose method of production must be read in the context of copious research and diverse social networks. Polyphonic House, exhibited here for the first time, also refers to the context and demonstrates the spatial and architectural orientation of Oliasson’s project. The object incorporates components of a camera obscura, so that the surrounding room and the movements of passing visitors can be observed in its interior.