Thomas Topham Petherbridge of Plymouth was an early land owner in Adelaide. His name was given to Topham Street, running on the site of his land between Currie Street and Waymouth Street. It is now a pedestrian mall, Topham Mall, and the Topham Link shopping arcade and Topham U-Park car parking station now sit on the site.
References
Thomas Topham Petherbridge Wikipedia(Text) CC BY-SA