We report on a two-dimensional hexagonal "honeycomb" network comprising barium-seamed metal-organic nanocapsules involving a hexameric assembly of pyrogallol[4]arene ligands. The incorporated barium ions act as spacers to generate a solvent-accessible void, hierarchical self-assembly having an individual void volume near 13 000 Å3. This work illustrates the surprising chemistry that remains to be discovered by integrating large or classically non-reactive metal ions within supramolecular assemblies, networks, and organic nanocapsules.