MTB downhill from Vallvidrera to Barcelona through Collserola park, on a path too narrow for a bike sometimes. Starting at train station of Vallvidrera Superior it goes down to Sant Just through Font de la Budellera, Revolt de les Monges, Baixador de Vallvidrera, Pantà de Vallvidrera, Font de l'Espinagosa, and corriol of Sant Just, finishing at Esplugues del Llobregat.