  Composite axion scenarios offer a robust field theoretic justification for
the existence of a Peccei-Quinn symmetry of high quality. We present a new
class of realizations that are naturally embedded in Grand-Unified Theories,
retain asymptotic freedom for all gauge groups, and protect the axion symmetry
up to operators of dimension 12. Our setup leads to a number of distinctive
signatures at low energies. First, additional composite scalars are predicted;
some of these are viable dark matter candidates for values of the axion decay
constant that are too low for the QCD axion abundance to be relevant. Second,
an approximate unification of the Standard Model gauge couplings takes place at
the axion scale, while leaving the actual quark-lepton unification at much
higher energies as usual. This suggests the existence of GUT relics with
Standard Model gauge quantum numbers at potentially accessible scales.
