This granite structure is located along the Esplanade. It's called the Cenotaph or known as also as "Our Glorious Dead".
Extract from the National Library Infopedia:
The Cenotaph located along Connaught Drive at the Esplanade, facing the old Courthouse, is a war memorial, which commemorates the sacrifice of the men who perished during World War I and World War II. It was unveiled on 31 March 1922 by his Royal Highness the Prince of Wales, Edward VIII.