Urban designers have long heralded the value of the public realm in creating stronger communities. Yet, their processes and decisions are based around data that is far removed from the community, outdated and/or based on surveys and feedback forums which are generally attended by the same group of people and which can be overtaken by lobbyists. If we want to create cities that place people at the centre, it is essential that we find data about what makes neighbourhoods connected and wholesome, neighbourhoods which provide safe spaces for their community to engage. Social data (data from social media, crowdsourcing, mapping platforms, review apps, etc) can give us an opportunity to understand how people engage in their communities and interact with the places around them. It can be used to provide insights into the social health of local places and identify vulnerabilities, to feel the heartbeat of the neighbourhood. I will talk about what social data is, some of the challenges of getting it and collating it, the data's strengths and weaknesses, and how we are trying using it to make cities more socially connected.