The Natural Science Museum occupies two spaces in a huge building overlooking a sloping garden on the Castellana. Much of the north wing is given over to temporary exhibitions: generally a couple of small-scale ones are held annually and a larger, more ambitious one, lasting about a year, is organised every 18 months. They tend to be hands-on, interactive and fun for kids. Permanently in this wing is 'Mediterranean Nature and Civilisation', a large exhibition of Mediterranean flora and fauna, illustrating the region's biodiversity. The smaller space to the south contains a simpler, more old-fashioned presentation of fossils, dinosaurs and geological exhibits. A replica of a diplodocus dominates the two-floor space, surrounded by real skeletons of a glyptodont (giant armadillo) and other extinct animals. The most distinguished skeleton here, though, is that of the Megatherium americanum, a bear-like creature from the pleistocene period unearthed in Luján, Argentina, in 1788.