Borders—political, institutional and cultural—have been central to the internationalization of heritage in the modern era. The concepts of heritage diplomacy and the border represent fertile analytical grounds for considering how the conservation and governance of heritage has been made and re-made in particular ways. Thinking through borders helps us to interpret why certain knowledge practices prevail, why heritage figures within diplomatic relations, or where and when cooperation either emerges or fails to emerge. In pursuing such themes, the paper thus seeks to conceptualize the internalization of cultural heritage by reflecting upon what are the changes when objects, people, and funding cross borders, and the diplomatic sensitivities that arise when heritage sites straddle them.