As a conjunction of tidal dynamics and rapid urbanisation, 193 acres of the future abandoned Oil refinery site on the Chao Phraya estuary offers a fresh opportunity for landscape architectural intervention in addressing multiple challenges of urban expansion, decaying ecology and hydrological fluctuation. Bangchak Public Park and Energy Museum is one of the feasible projects that could be a great solution to the problems as well as engaging and educating people at the same time. The purposes of this project are to create a massive public green area for recreation; to provide space for city-scale activities; to educate people, especially youths, about renewable energy and water remediation. The site is surrounded by polluted canals and river, 95% of the area is a contaminated concrete surface, therefore, the consideration of designing soil reclamation system and water remediation system are crucial. Research of this project consists of site surroundings, site transportation, population density, site potential, visual analysis, hydrology and climate, existing structure, remediation process, water treatment process, renewable energy, user and program analysis. The final design, based on research; composes of master plan, structural diagram, phrasing and circulation, remediated strategy, on-site water treatment, detail design; isometrics, perspectives and sections. The operative strategies can be applied to build a new landscape infrastructure that performs mixed hydro-ecological functions and responses to environmental shifts in diverse range of times and spatial scales.