Summary (from NESP Methods Brief Series): This methods brief focuses on access to recreational open space, which is a key component of mental health and wellbeing. This analysis maps the supply of publicly accessible open spaces relative to where people live. Regional priority areas for the creation of new open space through conservation are identified based on a metric representing the number of people who would benefit from new recreational open space if it were created in that area. Spatial datasets for these priority areas and associated metrics are available on ScienceBase.