This paper examines the planning of Ariel Sharon Park, Israel's largest metropolitan park, in light of the emergence of environmentalism in Israel. It identifies four periods of significance in the park's planning. First, during the first half century of statehood (1948–1998), and in accordance with the state's general environmental oversight, the area served as a derelict backyard for the evolving metropolis of Tel Aviv, with the Hiriya landfill as its focus. The second period started with the closure of the landfill in 1998. It followed the emergence of an environmental paradigm that emphasizes preservation of open spaces for recreation and human use, and resulted in the planning of the area as a ‘green lung’ or a recreational area. Following international trends, the third period (mid-1990s) is characterized by ecological planning, perceiving the park as a locus for various environmental services such as soil and water purification. Currently, the planning process refines the social and spatial connections between the park and the adjacent urban fabric, in accordance with the current discourse on social/ecological sustainability. Discussing Ariel Sharon Park as a case study, the paper traces the broad and general connections between planning and environmentalism within the unique social, political and ideological setting of Israel, and questions the limits of the current social sustainability discourse.