Pioneer Building on Nathan Road just south of Nullah Road. Given the clean appearance of the building and the electrical cable nearby, the photo was probably taken upon its completion. Notice the light pedstrian traffic and virtually absence of automobiles. Planners in those days did think ahead of their time.
Photo source: uwants.com - post #1999 by user 超級人物 - http://www.uwants.com/viewthread.php?tid=14833421&page=134#pid213706203