Congost River Nature · Granollers, Vallès Oriental, Barcelona The Congost rises at the Font del Regàs, in Collsuspina, fed by waters from the western escarpments of the Plana de Vic, and takes its name from the narrow gorge it carves as it crosses the Serralada Prelitoral, between the Montseny and the Cingles de Bertí. The gorge begins at the Gorg Negre, near Centelles, and continues through Aiguafreda and Figaró until it opens onto the Vallès plain at la Garriga; it then crosses the plain, passing through Granollers, and forms the Besòs river on joining the Mogent, at Montmeló. It is 41 kilometres long with an average flow of 0.56 m³/s, of Mediterranean regime and prone to flooding: the flood of 10 October 1994 recorded 750 m³/s at la Garriga. Its banks have long been the main communication route between the Vallès and Osona. Photo: El noi de la garriga (Public domain) What to see and do in Granollers