A ring of high forested hills, that separates the Dandenong Valley from the Yarra Valley, nurtures the source of the Mullum Mullum Creek. The high plateau is formed by the Wicklow Ridge to Reagh's Hill in the east, Bedford Road and Maroondah Highway in the south, and the Loughnan's Hill, Wonga Road ridge to the west. Commencing in Croydon south of Birt's Hill behind the Yarra Valley School, the Mullum Mullum Creek flows south downstream passing remnant orchards, bushland and parks through Ringwood and past Eastland Shopping Centre. Native hyacinth orchids and small grass trees hide in the remnant forests. The otter-like Rakali swims and fishes in the stream.
Butterflies live in the grassy and sedgy woodlands, and birds and possums are plentiful.
Drier mixed species forests gradually give way to Swamp Gums and Manna Gums as the Creek heads south. View Map of Significant Bushland 2. In the damp shadows, tall old growth riparian forests provide habitat for Koalas and many birds nest in ancient tree hollows. Maiden Hair ferns and Tree ferns thrive. On the drier hillsides orchids bloom and echidnas wander.