The syn and anti bismethano[14]annulenes have been used to test the accuracy of the semiempirical (PM3) and ab initio (HF and MP2), as well as density functional theory (BLYP and B3LYP) methods. Compared to experimental data, PM3 and HF overemphasize bond localized structures, while the correlated MP2 and density functional methods tend to favor overly delocalized aromatic structures. B3LYP computations give the best agreement with the available experimental data, they provide the most reliable estimates of the relative energies of aromatic and non-aromatic cyclenes. The calculated magnetic susceptibility exaltations and nucleus-independent chemical shifts (NICS) parallel geometric and energetic criteria. The methods were also applied to 1,6-methano[10]annulene and azulene.