  Using isobaric Monte Carlo simulations, we map out the entire phase diagram
of a system of hard cylindrical particles of length $L$ and diameter $D$, using
an improved algorithm to identify the overlap condition between two cylinders.
Both the prolate $L/D>1$ and the oblate $L/D<1$ phase diagrams are reported
with no solution of continuity. In the prolate $L/D>1$ case, we find
intermediate nematic \textrm{N} and smectic \textrm{SmA} phases in addition to
a low density isotropic \textrm{I} and a high density crystal \textrm{X} phase,
with \textrm{I-N-SmA} and \textrm{I-SmA-X} triple points. An apparent columnar
phase \textrm{C} is shown to be metastable as in the case of spherocylinders.
In the oblate $L/D<1$ case, we find stable intermediate cubatic \textrm{Cub},
nematic \textrm{N}, and columnar \textrm{C} phases with \textrm{I-N-Cub},
\textrm{N-Cub-C}, and \textrm{I-Cub-C} triple points. Comparison with previous
numerical and analytical studies is discussed. The present study, accounting
for the explicit cylindrical shape, paves the way to more sophisticated models
with important biological applications, such as viruses and nucleosomes.
