Public open spaces play a key role in urban environments, providing recreational opportunities, enhancing the quality of life, and contributing to the overall attractiveness of a neighborhood. Newly developed public open spaces on surrounding land value changes are important for urban planning and development. Within the last 10 years period most open spaces developed in the Colombo suburban area and there are clear land value changes in those areas. Bellanwila-Atthidiya Waras Ganga open space is one of the most attracted open space in the Colombo suburbs and significantly surrounding land values are changed after the project. This research aims to examine the effect on land values in surrounding area due to this project and research devotes a quantitative approach, using GIS based geo statistical analysis. Land value data, including sales transactions and property assessments, will be collected from relevant government agencies and real estate databases. The collected land value data was used to create geospatial maps using ArcGIS 10.8 spatial interpolation. Various proximity factors and demographic characteristics affected to change land values in this area, also considered for this analysis. Study results indicates, there is a significant relationship between residential land value changes in the lands surrounding public open space and it is 7.2% impact on land value changes The findings of this study provide valuable insights into the relationship between public open spaces and land values in the Colombo suburban area. The results are useful for urban planners, policymakers, and real estate developers about the potential economic benefits associated with public open spaces.