Natural environments (green and blue space) are associated with a range of health benefits, but their use is likely to be influenced by the presence of features, facilities and amenities and the condition/maintenance, or the natural environment quality. Most ‘quality’ assessment tools have focused on green spaces and their support for physical activity. This limits their utility for assessment of other natural environment typologies and uses (e.g., social, relaxation). We aimed to develop a tool for feasible, in situ assessment of diverse natural environments that might support a variety of uses, and to explore associations between natural environment quality and objectively measured amount of natural environment and neighbourhood-level socio-economic status (SES). This work was conducted as part of the PHENOTYPE project. Data were collected in 124 neighbourhoods in four European cities (Barcelona, Doetinchem, Kaunas, Stoke-on-Trent). The Natural Environment Scoring Tool (NEST) was developed using existing tools, expert input and field-testing. The final tool comprised 47-items across eight domains: Accessibility, Recreation facilities, Amenities, Aesthetics ? natural, Aesthetics – non-natural, Significant natural features, Incivilities and Usability; typology-specific Overall Scores were derived. In total, 174 natural environments, covering a range of typologies, were audited. Mean time to complete NEST was 16 ± 28 min. There was good inter-rater agreement. Mean domain scores showed some expected patterns by typology (e.g., higher Recreation Facilities scores in urban parks and formal recreation areas; lower Amenities scores in natural/semi-natural areas). Highest mean Overall Scores were observed for areas of blue space and woodland, the types of area that often lack the recreational facilities or amenities that can be dominant in physical activity-focused audit tools. There was a trend towards lower natural environment quality in neighbourhoods of lower SES, with some inter-city variation. Correlations between NEST scores and amount of natural environment indicated higher natural environment in areas with worse access. We recommend further testing of NEST in other locations in relation to use and health outcomes.