On a September afternoon, the permanent residents of Ibiza walked onto one of their most visited beaches and refused to leave — not as tourists, but as inhabitants reclaiming what the tourism economy had quietly taken from them. The act was simple and ancient: people standing in a place to say it belongs to them. Ibiza, an island of 130,000 souls now visited by millions each year, has become a mirror for a tension spreading across the world's most coveted destinations — between those who pass through a place and those who must live inside it.