This paper draws evidence from studies designed to explore the relationship between access to natural open spaces and physical activity, health, and quality of life. The research investigated patterns of woodland and green space visits for different kinds and levels of activity, relating these to perceptions, experience, and barriers to use by different groups across a range of UK contexts. Segments of the population targeted include deprived urban communities, black and minority ethnic groups within such communities, and older adults across different regions of Britain. The findings show certain consistent patterns in active use of natural environments, and in attractors and barriers to use. They suggest that natural open space offers opportunities for peace, relaxation, and social activities and, for many, physical activity is a secondary benefit, rather than a primary purpose in visits. Nonetheless, recent longitudinal work points to a causal relationship between improvements to the quality and accessibility of natural environments and levels of active use. Innovative conjoint analysis methods offer insights into what attributes of the physical environment might be most effective to change in such interventions and how they might be used to address health inequalities for different population segments.