Looking down into the Cogost de Collegats itÕs hard to credit the contrast between this intensely green ÔAlpineÕ vegetation and the Mediterranean ambience of the Pallars Jussˆ, which is just a few miles south at the far end of the ravine. The river Noguera Pallaresa passes through exceptionally varied landscape and climate zones in its short trajectory from the highest ranges to the plains beyond the Sierra de Montsec.