Prior to large scale subdivision, Mount Eliza was mainly a location for holiday homes, Mount Eliza Post Office opening on 15 November 1920. This began to change in the early half of the 20th century when many old estates were subdivided. One such subdivision was Ranelagh Estate, designed by Walter Burley Griffin and Marion Mahony Griffin in 1924 in tandem with the surveyors Tuxen and Miller.

Daveys Bay was named after James Davey who constructed a jetty in the 1840s to ship his produce to Melbourne. In 1909 the Daveys Bay Yacht Club was established, and winds its way to a walking track overlooking Mt Eliza Beach on the shores of Canadian Bay, which was named after three Canadians who owned a sawmill in the area in the 1950s. In 1928, the independent girls school Toorak College was built and is one of the oldest independent girls schools in Victoria. By the 1950s the shopping precinct began to develop and by the 1960s was a well established shopping village. Hollywood glamour came to Mt Eliza in 1959 when movie stars Fred Astaire, Gregory Peck and Ava Gardner arrived to shoot the Stanley Kramer film, On The Beach, based on the novel of the same name by British novelist Nevil Shute who had lived at nearby Langwarrin.

Adjacent to Sunnyside beach sits a historical property Morning Star Estate. Morning Star Estate is a distinctive example of a Victorian era mansion built as a rural or holiday retreat on the Mornington Peninsula, it incorporates a variety of picturesque styles including Tudor and Gothic revival.

Sunnyside estate (now Morning Star Estate) was originally purchased by Londoner Francis Alfred Gillett in 1865 a short time after he arrived in the colony in 1853. Gillett designed the Sunnyside mansion sometime around 1867-1870. In 1932 the property was purchased, with funds from a bequest, by the Catholic Church and became known as Morning Star Boys' Home. The boys’ home was developed into a country-training centre for delinquent boys, giving them exposure to the benefits of rural life. The boys later became involved in an extensive building program, which led to further developments of the property. Despite this, the mansion remained the dominant architectural feature of the property.

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Wikipedia