In: The Local Group as an astrophysical laboratory. Proceedings of the Space Telescope Science Institute Symposium, held in Baltimore, MD, USA, May 5-8, 2003, edited by Mario Livio, Thomas M. Brown. Space Telescope Science Institute symposium series, Vol. 17. Cambridge, UK: Cambridge University Press, ISBN 978-0-521-84759-9, ISBN 0-521-84759-1, 2006, p. 178 - 195
We analyze the properties of the Massive Young Clusters in the Local Group, concentrating on the youngest segment of this population and, more specifically, on the two best studied cases: 30 Doradus and NGC 604. 30 Doradus is a Super Star Cluster and will likely evolve to become a Globular Cluster in the future. NGC 604, on the other hand, is a Scaled OB Association that will be torn apart by the tidal effects of its host galaxy, M33. Given their extreme youth, each cluster is surrounded by a Giant H II Region produced by the high ionizing fluxes from O and WR stars. The two Giant H II Regions are found to be rather thin structures located on the surfaces of Giant Molecular Clouds, and their geometry turns out to be not too different from that of classical H II regions such as the Orion or Eagle Nebulae.