We all-too-often think of the spaces of geography as areas, not volumes. Territories are bordered, divided and demarcated, but not understood in terms of height and depth. 'Secure the area' is a common expression for the military and police, but what happens if another dimension is taken into account and we think what it means to 'secure the volume'? This article draws on the emergent literature on vertical geopolitics and Peter Sloterdijk's work on spheres, but also looks at what happens below the surface, with a particular focus on tunnels. Using Paul Virilio's work, and some examples from the West Bank and Israel's border with Lebanon, it demonstrates how we need to think volume-think about volume, through volume, with volume-rather than simply the vertical to make sense of the complexities of territory today.