The culture of peace is essential for building sustainable societies, promoting human well-being, and enhancing human rights. Sub-national actors, such as provincial governments, NGOs, the media, academics, and committed individuals, play a crucial role in promoting the culture of peace. In this session, we will explore the role of sub-national actors in promoting the culture of peace and showcase best practices from Jeju. In particular, we will examine how Jeju has been spreading the culture of peace through its efforts to inscribe the Archives of Jeju 4·3 on UNESCO's Memory of the World Register.