  We report the discovery of a hitherto undetected population of Wolf-Rayet
stars in the young galactic open cluster Westerlund 1. Optical spectroscopy of
the cluster identified 11 such objects; provisional classification suggests
that 6 are nitrogen rich (WN) and 5 carbon rich (WC). Including the previously
identified Blue, Yellow and Red Super- & Hypergiants, Westerlund 1 clearly has
a very rich population of massive post-Main Sequence objects. To date, the
post-MS population of Westerlund 1 is significantly larger than that of any
other galactic young open cluster - with the possible exception of the Arches -
implying that it is potentially amongst the most massive young clusters yet
identified in the Local Group.
