Over the past decades, Europe has experienced several terrorist attacks, proving that this threat is still real and serious, while perpetrators are finding new methods to penetrate current security measures. Although grave attacks have so far been rather infrequent, it is still a reality that EU citizens may be suddenly caught up in a terrorist incident, while at the stadium, shopping in a mall, commuting, visiting a cultural venue, or in any other public space. Besides, more terrorist attacks are associated with lower levels of life satisfaction and happiness among the EU population. One in five people in the EU are indeed very worried about a terrorist attack in the next 12 months. Terrorist attacks also lower EU citizens’ trust in fellow citizens, national political, legal and police institutions. SAFE-CITIES aims to support excellence in the protection of public spaces, by delivering and demonstrating a Security and Vulnerability Assessment framework, empowered by a decision-support platform for its implementation, in 4 use-cases across 5 EU countries. This will allow for simulation of complex scenarios, crowd behaviour and attacks in any space within a realistic virtual 3D environment, enabling end-users to perform comprehensive and dynamic risk and vulnerability assessments of the site investigated, to identify potential vulnerabilities against a wide number of threats and support the full engagement and cooperation of public and private actors, including citizens, into the elaboration of strategies, to make public spaces secure while preserving their open nature. The Consortium brings together 17 partners from 9 countries (Italy, Cyprus, Netherlands, Greece, Poland, UK, Belgium, Finland, Slovenia). To effectively carry out the 32 months project, the project team includes local and regional authorities, Police authorities, First Responders organizations, RTOs and academia, CSO, security industry cluster association, and high-tech SMEs specialised in security.