  A conformal field theory representing a four-dimensional classical solution
of heterotic string theory is presented. The low-energy limit of this solution
has U(1) electric and magnetic charges, and also nontrivial axion and dilaton
fields. The low-energy metric contains mass, NUT and rotation parameters. We
demonstrate that this solution corresponds to part of an extremal limit of the
Kerr-Taub-NUT dyon solution. This limit displays interesting `remnant'
behaviour, in that asymptotically far away from the dyon the angular momentum
vanishes, but far down the infinite throat in the neighbourhood of the horizon
(described by our CFT) there is a non-zero angular velocity. A further natural
generalization of the CFT to include an additional parameter is presented, but
the full physical interpretation of its role in the resulting low energy
solution is unclear.
