  The sequence of intertwined T-S-T duality transformations acting on the 4D
static uncharged black hole leads to a new black hole background with horizon
and singularity exchanged. It is shown that this space-time is extendible too.
In particular we will see that a string moving into a black hole is dual to a
string leaving a white hole. That offers the possibility that a test-string
does not see the singularity.
