The site was also a Customs office, a base station of the overland telegraph, and is noted for its architectural and historical significance.

The building is situated on Stirling Terrace, opposite Spencer Street, on a multilevel site that overlooks Princess Royal Harbour.

The original building was completed in 1869, after requests from the Government Resident to the administration in Perth, Western Australia.

It was an extension that was sympathetic to the earlier building, incorporating the same local materials, and successfully accommodating its multileveled situation.

The first telegraph pole was ceremoniously placed by Governor Weld, where it remains on a monument commemorating the engineering milestone.