In the design research workshop Mapping Invisibility, undocumented immigrants and other participants undertook collective mapping in Amsterdam. The aim was to investigate the day to day practices of undocumented immigrants and to look for ways to make parts of those practices visible and perceptible for others – precisely because much of the life of the undocumented is about invisibility. In the workshop (at least) two cartographers – an undocumented immigrant (guide) and a participant (guest) – walked the city together. The walk was tracked via a web application on a mobile phone with GPS and visualised in real time on a digital map that could be viewed by others on a website. The undocumented immigrant guided the participant to places which represented a certain emotion or feeling for them. On the map, as it evolved, particular places would light up, representing the feeling associated with them. Along the way, the conversation between guide and guest was recorded, and these audio recordings stored in a location-based archive that makes ‘unheard’ stories available to ‘the public’. At the departure point of the original walk, using a mobile phone as a navigational device, at any time, invisible storylines can be downloaded as mp3s. The story remains audible as long as the listener stays on the same route.