  General Relativity provides us with some solutions for rotating black holes.
However, there are some problems associated with them: the appearance of
singularities, the possibility of violations of the cosmic censorship
conjecture, the existence of regions where the mass acts repulsively and the
violation of causality. Many authors consider that these problems reveal the
existence of certain limits in the applicability of General Relativity. For
instance, it is believed that the same existence of singularities in the
classical black hole solutions is a weakness of the theory and that a full
Quantum Gravity Theory would provide us with singularity-free black hole
models. In this paper, the generic properties of the interiors of
singularity-free rotating black holes are analyzed. Remarkably, it is shown
that they are devoid of any of the aforementioned problems of the classical
solutions.
