In 1931, replacing a small building of the same name, architects Emley and Williamson used modern materials and Art Deco motifs for a new "Castle" in Eloff Street, which was then the city's most fashionable shopping street. Pre-cast concrete blocks provide a sense of strength and endurance; the central attic tower hints at a stronghold of the fortress, the keep. The flagpole right at the top which made it the tallest building in Johannesburg at the time enhances the notion of a citadel with pennant flying aloft.