Serra de Collserola is the name of the mountain range between the rivers Besòs and Llobregat. These mountains separate Barcelona from the Vallès plain and their tallest peak is the Tibidabo, at 512 m. It is the largest metropolitan park in the world - 8 times larger than the Bois de Boulogne in Paris, and 22 times larger than Central Park in New York.
Forat de Vent
One of the climbs with low traffic exiting Barcelona and the start of a classic loop through Collserola park. Forat del Vent as locals call it is officially named “Turó de Valldaura” and is an ascent just under 4 km at 5% average which is quite consistent with no real steep ramps. That said it also does not give you any chance of recovery as the road continuously rises. Two viewing points give you panoramic views on Barcelona and specifically the nearby velodrome (worth a visit!). After passing under the bridge connecting the Carretera de les Aigües hiking and mountain bike path you will begin a fast descend through the forest until the village of Cerdanyola. There a little recovery is possible while you head to Sant Cugat after which you will climb mount Tibidabo from the west side.
Probably the most climbed hill near Barcelona. The views over the city are a true gift, especially during an early morning sunrise ride. After leaving Barcelona riding Via Augusta you will follow the BV-1462 to Vallvidrera. The first 200-meter stretch at 10% is a good warmup for the rest of the 6.8km climb which averages at 6%. Here you will certainly see some local cyclists flying up the hill or perhaps you can catch their wheel and draft along. After 3,5 km when you arrive at Vallvidrera keep heading up to Tibidabo, which houses the oldest still functional amusement park in Europe. Again a steep section after leaving the village and after recovering a bit you will have the option to climb to the summit taking the parking approach, loved/hated by local cyclists for its +20% ramp or take the easy way straight on and around the amusement park.