7 Social sustainability and witnessing difficult heritage Ross J. Wilson Abstract The legacy of war, colonialism, oppression and violence in the modern era is written into contemporary society. In the tangible and intangible heritage of buildings, objects, language and culture, there are points of engagement with the past that reference pain, trauma and unresolved issues that are divisive within democratic states. In response to these difficulties, governments, institutions and the wider population may resort to avoidance and obfuscation. However, exhibitions, displays and heritage sites provide a location where witnesses to the past can be formed who will testify to the abuse of power and recognise the suffering of others to create sustainable democracies and communities. This chapter will examine the representation of conflict in the 20th century across museums to identify narratives of evasion and practices of engagement. By using the position of the ‘witness’ and exploring the philosophical position of ‘testifying’, this chapter explores how difficult heritage can be mobilised to work for contemporary society. Introduction This chapter demonstrates how studies of cultural heritage can take a leading role in debates regarding social sustainability. This is especially the case with aspects of ‘difficult heritage’, the tangible and intangible remnants of the traumatic events of the modern era. It is these objects and sites that require dialogue and engagement, they need a mode of witnessing that recognises the inequalities and divisions that persist in societies. This way of engaging and orientating individuals and communities with the past as a means of ensuring well-being, democracy and fostering a truly inclusive civil society is key for issues of sustainability. Whilst studies of sustainability have tended towards ecology, scholars within the arts and sciences, who are seeking to change the agenda away from purely environmental issues, have highlighted how an anthropocentric approach is needed to address the challenges that societies across the world will