Terrorism and atrocities have scarred the public memory in the late twentieth and early twenty-first centuries. Three atrocities, the 1995 Oklahoma City bombing, the 1996 massacre at Port Arthur Historic Site in Tasmania, Australia, and the 2002 Bali bombings, had a significant impact on the communities they most affected. How did the differing governments and communities at these sites respond to the sudden loss of life? How were the competing agendas of these groups managed ? Are there shared and distinctive characteristics in the memorialisation of atrocitites across these countries at the turn of the millenium? In responding to these questions, this study analyses cultural differences in memorialisation at contemporary atrocity sites. It examines the differing responses at the case study sites to the planning and the timing of memorials, the engagement of those affected, the memorial designs and the management of the memorials, including tributes. It is an original comparative study of contemporary memorialisation by a heritage professional directly involved in the management of memorials at contemporary atrocity sites. The original research includes the identification of the role the internet in contemporary memorialisation, an in-depth analysis of the memorialisation of the 1996 massacre at Port Arthur Historic Site, and the memorialisation in Bali and across Australia of the 2002 Bali bombings. It extends the current scholarship on the memorialisation of the Oklahoma City bombing through identifying the impact of the internet in the memorialisation and in the timeframe of the analysis through to the 15th anniversary in 2010. The comparative analysis of the management of tributes at all the sites identified issues not previously considered in Australian scholarship: that tributes and the response to them is part of the memorialisation and management of contemporary atrocity sites. A combined research method based on an interpretive social science approach was adopted. A range of methodogies were used, including literature reviews, analysis of electronic material, site visits, unstructured in-depth interviews, and participant-observation at memorial services. Studies on history, memory and memorialisation provided the framework for my analysis and led to an original proposal, that all three sites have shared histories of the memorialisation of war and ‘missing’ memorialisation. These shared histories, I argue, strengthened the justification for this comparative study. This comparative study identified differences across the case study countries in the designs of the built memorials, in legislation enacted after the atrocities, the responses to the perpetrators, the marking of anniversaries, and in the management of tributes left at the sites. These…