From the Apartheid wall in Palestine to the digital paywall, from memorial murals in Jamaica to the increasingly tall glass facades of modern office blocks, walls testify to the tumult of history and humanitys ceaseless urge to communicate and to sow division. They force us to reflect on the paradoxes of openness and isolation, of enclosure and exclusion. In a world drowning in borders, barriers and barbed-wire fences, this issue of MacGuffin pauses for thought and asks: What exactly do we want to express or protect? And why?