  High-mass stars are major players in the chemical and dynamical evolution of
galaxies, and young massive clusters are the natural laboratories to study
their evolution and their impact on star formation processes. Only in recent
years have we become aware of the existence of numerous massive (M_cl >
10000M_sun) clusters in our Galaxy. Here I give a review, rather biased towards
my own research interests, of the observational and theoretical efforts that
have led to a description of their properties, and present an overview of the
two (perhaps three) starburst regions known outside the Galactic Centre
neighbourhood: the Scutum Complex, its putative counterpart on the far side of
the Long Bar, and the starburst cluster Westerlund 1.
