during the course of the Project, were identified as important factors for enhancing their work and their impact in terms of preventing violence. The overall idea is to support NPMs in finding effective tools to investigate the root causes of violence, or in other words, the more indirect or hidden aspects that enable violence, such as structural, situational and cultural factors. To this end, the Handbook incorporates innovative methodologies, such as systemic questions and appreciative inquiry, as these can be particularly effective for the monitoring of violence and its prevention. We hope the Handbook will contribute to enhancing the impact of the work that NPMs undertake for the prevention of violence in prisons and, ultimately, support the improvement of prison conditions in the EU.