  We present the results of lattice QCD calculations of the magnetic moments of
the lightest nuclei, the deuteron, the triton and ${}^3$He, along with those of
the neutron and proton. These calculations, performed at quark masses
corresponding to $m_\pi \sim 800$ MeV, reveal that the structure of these
nuclei at unphysically heavy quark masses closely resembles that at the
physical quark masses. In particular, we find that the magnetic moment of
${}^3$He differs only slightly from that of a free neutron, as is the case in
nature, indicating that the shell-model configuration of two spin-paired
protons and a valence neutron captures its dominant structure. Similarly a
shell-model-like moment is found for the triton, $\mu_{{}^3{\rm H}} \sim
\mu_p$. The deuteron magnetic moment is found to be equal to the nucleon
isoscalar moment within the uncertainties of the calculations.
