Nest-egg: A nestlike C4-symmetric [Co24] metallamacrocycle is assembled by bridging eight Co3–sulfonylcalix[4]arene subunits with sixteen 1,2,4-triazolate ligands (see figure). It exhibits a square antiprism polyhedron topology and antiferromagnetic properties. Interestingly, a new mode of supramolecular association of water molecules and an interesting H2O⋅⋅⋅(MeOH)5⋅⋅⋅ H2O supramolecular chain exist in the crystal lattice.