As extinction rates accelerate, zoos have evolved from places for public entertainment to centres of conservation, education and research. Zoo-based learning is inherently ‘free-choice’, meaning it is subject to visitors’ personal experiences, knowledge and agendas. Naturalistic, ‘immersive’ exhibits are commonplace in modern zoos and should provide the sense of discovery that maximises free-choice learning. Chester Zoo is developing ‘Grasslands’, a multi-species, immersive exhibit based on African savannahs, due to open in 2023. To assess the educational potential of Grasslands, this