Part of the Kings Domain feature the Alexandra Gardens, designed by Carlo Catani that are situated between the Yarra River and Alexandra Avenue. This area became a public park in 1904 when the garden was designed around the existing rowing club boat sheds and the Army Engineers Depot.

While Catani did design the garden, much of the credit for the its success and popularity belongs to the curator, George William Cooper (1880 - 1967). Cooper, whose position with the Public Works Department came by way of William Guilfoyle’s recommendation. At that time William Guilfoyle was the curator of the Melbourne Botanic Gardens, and on occasion was known to have also offered advice to Catani. W. Cooper and his father were noted to have laid out Dame Nellie Melba’s Coombe Cottage gardens at Coldstream, designed by Guilfoyle and surveyed by Catani. For around seventeen years Cooper worked with Carlo Catani. In 1917, upon Catani’s retirement, George took up the position of Superintendent of Parks for Sydney City Council. He later had a gardening show on Radio 2BL and wrote gardening columns for various newspapers.

Also forming a significant component of the Domain gardens are the Queen Victoria Gardens, completed in 1913, of which Catani was a major contributor. The Australasian newspaper of May 2, 1908 neatly summarises the success of the Alexandra Gardens: 'For many years this spot was a desolation and an eyesore; it has been converted into quite a fairy-like place, full of beautiful flowers and shrubs, rockeries, and well-kept lawns, and all within a few minutes' walk of the Melbourne Town-hall'.

Central to the Alexandra Gardens is the Federation Star Bed, consisting of a six-pointed star representing the Commonwealth with interposing circular beds signifying each state.

This rose bed, a symbol of Federation, was planted out with involvement of the National Rose Society in 1906. Amidst the 220 roses, the State colours displayed were pink for Victoria, white for New South Wales, crimson for South Australia, yellow for Tasmania, bronze for Western Australia and a light crimson for Queensland.

One area of the gardens was the Henley Lawn where spectators by the thousands lined up to watch the annual Henley-on-Yarra rowing regatta.

The lawn was laid out by Catani and Cooper in Autumn 1908.