  Solutions to the equations of motion of the low energy, effective field
theory emerging out of compactified heterotic string theory are constructed by
making use of the well-known duality symmetries. Beginning with
four-dimensional solutions of the Einstein-massless scalar field theory in the
canonical frame we first rewrite the corresponding solutions in the string
frame. Thereafter, using the T and S duality symmetries of the low energy
string effective action we arrive at the corresponding uncharged, electrically
charged and magnetically charged solutions. Brief comments on the construction
of dual versions of the Kerr-Sen type using the dilatonic Kerr solution as the
seed are also included. Thereafter, we verify the status of the energy
conditions for the solutions in the string frame. Several of the metrics found
here are shown to possess naked singularities although the energy conditions
are obeyed. Dual solutions exhibit a duality in the conservation/violation of
the Null and Averaged Null Energy Conditions (NEC/ANEC), a fact demonstrated
earlier in the context of black holes (hep-th/9604047) and cosmologies
(hep-th/9611122). Additionally, those backgrounds which conserve the NEC/ANEC
in spite of possesing naked singularities serve as counterexamples to cosmic
censorship in the context of low energy, effective string theory.
