 They were all opened at once on 28 February 1966, at which time Line C was renamed Line 6; in 1984 it became U6.The Alt-Tempelhof station was finished to a design by Bruno Grimmek, who retired soon afterwards; his successor as architect with the Berlin U-Bahn, Rainer Rümmler, assisted with this station and was responsible for the others in the line extension.Like all the extension stations, it has a centre platform and exits at each end and is utilitarian in appearance.