This research explores how ambient displays [1] can be designed to promote human-to-human interaction in semi-public spaces, rather than detract from it. The research aims to provide design guidelines for designing physical ambient displays that can act as conversation starters and foster connectedness between "known strangers" who visit frequently the same spaces. As humans we live and interact in diverse physical spaces, and through a range of information, we each construct a unique perception of these places. It should come as no surprise that the individuals we share these places with, whether they are friends, co-workers, or familiar strangers, greatly influence how we perceive them. Although we often see them but not directly interact with these “known strangers” [2] they have significant impact on us. Fostering interaction among strangers in semi-public spaces could positively impact the sense of community and the mood of the users. The research explores the patterns of beneficial but challenging interactions that are triggered by ambient displays, considering both design possibilities and challenges. The aim is to propose concerns and strategies that designers can use to generate such outcomes. Semi-public buildings typically promote community interactions, but declining public space interactions, exacerbated by social over-stimulation, pose challenges. Meaningful stranger interactions demand thoughtful integration of physical features into public space design, providing spaces for pause, seating, and reflection. This study started with a literature, semi-structured interviews and short ethnographic research to better understand information needs and interactions with "known strangers" [2] in semi-public settings. To explore possible interactions triggered from ambient displays, prototypes were then created and experimented in a lab setup, followed by semi-structured interviews.