We explore issues of social context and interaction between digital and physical museum visitors, using as a focus of discussion the City project, itself set within a larger interdisciplinary project called Equator. We look at collaborative environments that span different media, in particular handheld mobile devices, Web-based hypermedia and 3D virtual environments. We discuss two main strands in our research: the methods and results of two pilot visitor studies in two cultural institutions in Glasgow?the Lighthouse and the House for an Art Lover?and the development of our prototype system which establishes three-sided collaboration between physical, Web and virtual environment visitors. We then present preliminary results and issues arising from our on-going system development and user trials. We conclude with future plans for further system evaluation and deployment.