Since Angkor became a World Cultural Heritage Site in 1992, multiple international institutions have been involved in the conservation of its endangered monuments. Archaeological research has also been conducted in tandem with these restoration works. Nonetheless, public engagement with the local communities in Angkor remains negligible beyond providing employment as laborers in the restoration and excavation projects. This paper offers insights from my personal experiences working with Japan's Sophia University Angkor International Mission (Sophia Mission) in conservation, capacity building, and community engagement. I argue that building a meaningful and sustainable collaboration project requires a good working relationship with both the local authorities and communities living around the project areas. This relationship includes the involvement of local communities in decision-making, research design, and promoting heritage education by both local and international specialists.