This article describes an example of science engagement striving for social justice by invigorating neglected spaces. The pop-up science centre “Knowledge◦Room“ in Vienna encourages learning, participation and engagement and provides accessibility to different groups regardless of their background. Based on a case-study of a bottom-up event at the Knowledge◦Room, we show how science communication can create a trust-based connection with disadvantaged groups in society and inspire their curiosity in science. We argue that science communication can be used as a tool for advancing social justice in the wider sense and facilitate encounters between diverse groups within society.