For several centuries, Taiwan was a frontier island, a place where indigenous, Austronesian peoples and their cultures met, faced off against, and cooperated with ethnic Chinese newcomers from the Asian mainland. There was a conceptual boundary marked on maps and a physical one as well, marked by boundary stones, watchtowers, and earthen barriers beyond which imperial Chinese subjects were not to settle. But in practice, like all frontiers, this was a porous boundary, and it was one that shifted over time with migration. Through a new exhibit called “Once Upon a Time in the Frontier”, the National Taiwan Museum is exploring what this frontier actually was, how it changed the peoples on both sides, and how it came to an end. Museum researcher Wu Bai-lu is with us today as a guide to Taiwan’s old frontier.