Volvo Photo Locations Part 350 Wenner-Gren Center is a tower and building complex in Vasastaden, Stockholm, Sweden. The building was constructed 1959–1961, and opened in 1962. The Center consists of three buildings named Helicon, Pylon and Tetragon. Pylon is a high tower, Helicon is a lower semicircular part surrounding the tower, and Tetragon is a […]