The original Perth Museum was built in 1822-1824.
The current building in Bridge Lane was required to house the amalgamation of the Marshall Monument collection with that of the PSNS. On opening the new Perth Museum in the former City Hall in 2024, this will become Perth Art Gallery.
The Perth Art Gallery which had previously been sited on the top floor of the Sandeman Library was included to form the Perth Art Gallery and Museum. The statue is of Thomas Hay Marshall who as Lord Provost did much to shape Perth as it is to-day stands in the rotunda.
The plaque provides details of the date of the official opening of the extension to the Art Gallery and Museum and other relevant information.