The packing structures of macroporous ordered siliceous foams (MOSFs) are systematically investigated by using a 3D electron tomography technique and the nanostructural characteristics for layered MOSFs are resolved. MOSF materials adopt an ordered 2D hexagonal arrangement in single-layered areas, regular honeycomb patterns in double-layered samples, and polyhedric cells similar to a Weaire-Phelan structure in multilayered areas, all following the principle of minimizing surface area, which is well understood in soap foams at the macroscopic scale. In surfactant-templated materials, liquid-crystal templating is generally applied, but here it is revealed that the surface-area-minimization principle can also be applied, which facilitates the design and synthesis of novel macroporous materials using surfactant molecules as templates.