Across the world, cultural heritage sites hold layers of stories that are often overlooked or unseen. How might these hidden narratives be revealed using Augmented Reality (AR)? At Santa Clara University, the monuments, buildings, and Mission Church highlight the Catholic heritage of our campus, but almost no recognition exists for the Ohlone Native Americans who continue to steward the land the university was built on since time immemorial. Together with the Muwekma Ohlone Tribe, our cross-disciplinary team launched the Thámien Ohlone AR tour, a webAR campus-wide tour that leverages Niantic’s 8th Wall and Lightship VPS to reveal these invisible histories and spur visitors to question which stories get recognized and how. This talk describes challenges and opportunities for creating large-scale AR experiences for social justice that are accessible to mass audiences. Drawing on our experience creating the Thámien Ohlone AR tour, we provide lessons for leveraging AR to transform the engagement with cultural heritage sites.