  The strong electromagnetic fields carried by relativistic highly charged ions
make heavy-ion colliders attractive places to study photonuclear interactions
and two-photon interactions.
  At RHIC, three experiments have studied coherent photoproduction of $\rho^0$,
4$\pi$, $J/\psi$, $e^+e^-$ pairs, and $e^+e^-$ pairs where the electron is
bound to one of the incident nuclei. These results show that photoproduction
studies are possible, and demonstrate some of the unique possibilities due to
the symmetric final states and the ion targets. The LHC will reach
photon-nucleon energies many times higher than at HERA; these collisions can be
used to measure the gluon distributions in nuclei at very low Bjorken$-x$,
where shadowing and gluon saturation may become important; LHC $\gamma\gamma$
collisions may also be attractive places to search for some types of new
physics. ATLAS, CMS and ALICE are all planning to study photoproduction. After
introducing the principles of photoproduction at hadron colliders, I will
review recent results from RHIC on meson and $e^+e^-$ production, and then
discuss prospects for studies at the LHC.
