  The classical Heisenberg antiferromagnet with uniaxial exchange anisotropy,
the XXZ model, in a magnetic field on a simple cubic lattice is studied with
the help of extensive Monte Carlo simulations. Analyzing, especially, various
staggered susceptibilities and Binder cumulants, we present clear evidence for
the meeting point of the antiferromagnetic, spin--flop, and paramagnetic phases
being a bicritical point with Heisenberg symmetry. Results are compared to
previous predictions based on various theoretical approaches.
