This paper will use a metaphor based on the ecological definition of the “ecotone” to examine the transition zones that occur around the edges of three of Sydney’s major parklands – Centennial Parklands (CP), the Sydney Olympic Parklands (SOP) and the Western Sydney Parklands (WSP). All three parklands are experiencing to a greater or lesser degree, change in the surrounding human habitat zones. In all three cases, the parklands under consideration experience edge effects related to abrupt boundary definition by major roadways. In the case of the WSP a major new roadway (the M7) will in fact dissect it. The paper explores how, for example, have edge conditions affected access to these parklands, use patterns and physical evolution over the years. The authors take the view that there is significance in conceiving of a park-city “edge effect” and that it should be given more consideration in planning our cities and suburbs.