The Sphinx Memorial in Ku-ring-gai Chase National Park is the unique legacy of a World War I Anzac soldier. 

The Sphinx Memorial was carved by Private 5756 William Thomas Shirley while convalescing at the Lady Davidson Hospital in Turramurra. 

Hewn from surrounding bush sandstone, the sphinx was carved between 1924-26, and is about one-eighth the size of the Great Sphinx in Egypt.

Local historians know little about Shirley’s early life. He was born between 1865 and 1867 and likely emigrated to Australia before 1901, where he worked as a stonemason and builder. 

In January 1916, William Shirley enlisted in the Australian Imperial Force (AIF) at Casula, and was assigned to the 18th Reinforcements, 13th Battalion. He travelled to England aboard the HMAS Clan McGillivray in May 1916, eventually leaving for France on March 20, 1917.

Shirley’s service in France was short-lived, however. In April, he was admitted to a hospital in Rouen after developing an upper respiratory tract infection. He was already suffering from tuberculosis, but the distress of military service combined with snowy weather conditions exacerbated his condition. 

Shirley was eventually transferred to Southwark Military Hospital in England, indicating the seriousness of his condition. Hospital records show he was suffering from “debility and pleurisy”. Shirley returned to Australia in August 1917, and by November he was formally discharged from service.  

Shirley never fully recovered from tuberculosis, and in January 1924 he was admitted to the Lady Davidson Hospital in Turramurra. It was here that Shirley began carving out the sphinx and two pyramids in the nearby bushland. 

He spent the next two years working on the project, dedicating a few hours a day to his work, with intermittent rest periods where his deteriorating condition left him bedridden. It wasn’t long until his work captured the interest of others: a journalist from the Sydney Morning Herald reported the event in 1924, when Shirley was just several weeks into the project. 

Shirley did not live to see his memorial unveiled to the public on May 3, 1931. 

He had passed away three years before, on August 27, 1929. 

The Sydney Morning Herald reported Shirley’s passing, writing: “The carving stands as a permanent memorial to the skill and patience of a brave sufferer, who contracted tuberculosis, following on war service.” 

However, factual inaccuracies within this Sydney Morning Herald article has led to many myths around the Sphinx Memorial. For example, it is widely believed that Shirley was inspired to carve a sphinx after visiting Egypt during his military training or leave. 

However, the Ku-ring-gai Historical Society has closely examined World War I Service records, Battalion histories and censuses to disprove this narrative. The Gallipoli battles were over by the time Shirley enlisted in the AIF, and therefore he never saw the Great Sphinx of Giza in person. 

It was also reported that Shirley was severely gassed during the First Battle of Bullecourt (11th of April 1917), leading to his hospital transferral and eventual discharge from service. 

The Ku-ring-gai Historical Society also contest this theory, as their research has proved that gas was not used in that specific battle. Local historians therefore suggest that Shirley developed some sort of upper respiratory tract infection, aided by the snowy weather conditions. 

The Sphinx Memorial is located on Sphinx Road, near Lady Davidson Hospital in North Turramurra. The site can be accessed on the Sphinx Memorial to Bobbin Head walk track.