In this paper, we analyse the Second World War (WW2) and the Holocaust as genocide during WW2 as sensitive topics in history teaching as perceived by 719 teachers from Austria, Belarus, Estonia, Finland, France, Germany, Israel, Italy, Serbia and the Netherlands. Using the thematic content analysis of open answers to an online questionnaire we explore the reasons for the sensitivity of these topics. The reasons for sensitivity were found to lie in cognitive and emotional barriers to treating the atrocities, violence and discrepancies between different perspectives on WW2 of social memory groups. A relatively new dimension, confirmed by the research, is the problem of the aestheticisation of the violent past. This can lead to banalisation and even legitimisation of the violence and aspects of the violence that pupils perceive to be fascinating. The results are discussed in the framework of multi-layered collective memory.