This paper introduces the intangible heritage and cultural values the Boon Wurrung have to Nerm (Port Phillip Bay) around which Melbourne resides. Before European colonisation of this landscape, the Boon Wurrung, a part of the greater Kulin Nation of the Melbourne region, were custodians of this Country (birrarang-ga) looking after it in anticipation of the return of their ancestors. At this time Nairm was an expansive open woodland grassland plain dissected by a braided riparian freshwater river (Birrarang) filled with lagoons and lakes, with the streams of Birrarang (Yarra), Werribee and Maribyrnong feeding into this river. The Boon Wurrung Country, then and now, stretched from the present Port Phillip Bay to Wilsons Promontory and included the southern portions of metropolitan Melbourne down to Western Port and the Mornington Peninsula. As told by the Boon Wurrung, before colonisation Nairm was created by Bunjil, at the time of fighting and chaos amongst the Kulin Nation peoples, letting the waters of Bass Strait to enter and flood this plain creating the present salt water Bay and its marine environment. This paper introduces the Boon Wurrung peoples, their overarching cultural relationship to this place and their Country, and the intangible values and stories of this community that interweave the creation of Nairm that is integral to and sustains their culture today. This narrative is positioned within contemporary geological, spatial and Western cultural heritage values and explanations that tells of the Holocene era transformative creation of the Bay and its environmental changes, and how the Bay is located today in the Boon Wurrung sense of their cultural heritage.