The rise of ubiquitous computing (UbiComp), where pervasive, wireless and disappearing technologies offer hitherto unavailable means of supporting activity, increasingly opens up ‘opportunity spaces’. These are spaces where there is no urgent problem to be solved, but much potential to augment and enhance practice in new ways. Based on our experience of co-designing novel user experiences for visitors to an English country estate, we discuss challenges for PD in such an opportunity space. Key amongst these are how to build a working relationship of value when there are no urgent requirements; how to understand and scope the space of opportunities; and how to leave users with new resources of value to them. Author Keywords Participatory Design, ubiquitous computing, case study. ACM Classification Keywords H5.m. Information interfaces and presentation (e.g., HCI).