  We present a technique for addressing single NV$^{-}$ center spins in diamond
over macroscopic distances using a tunable dielectric microwave cavity. We
demonstrate optically detected magnetic resonance (ODMR) for a single NV$^{-}$
center in a nanodiamond (ND) located directly under the macroscopic microwave
cavity. By moving the cavity relative to the ND, we record the ODMR signal as a
function of position, mapping out the distribution of the cavity magnetic field
along one axis. In addition, we argue that our system could be used to
determine the orientation of the NV$^{-}$ major axis in a straightforward
manner.
