Memorialising lives, deaths and events in landscapes can be authorised, official and highly regulated, or spontaneous, unsanctioned and anti-authoritarian. Interpreting and connecting two sites spanning the Pacific Ocean, this paper explores the inscribed and affective landscapes of Angel Island, San Francisco, and North Head, Sydney. Both sites encompass multivalent histories of defence, quarantine, immigration and leisure. Both also host a continuum of mark-making practices, from informal graffiti to monuments aspiring to direct national narratives. Elaborating the rich and complex layering of histories at each site, we trace the semiotic and emotive circuits marked by their endorsed and vernacular inscriptions. In particular, we question the work done when individual or even surreptitious texts are appropriated – or marketed – within formal narratives of inclusiveness, reverence and homogeneous nationalism. Drawing upon scholarship from archaeology, history, geography and heritage studies, this analysis argues that formalised commemoration never escapes the potential for counter-readings – that authority and authorship never entirely coincide.