La Pedra de les Orenetes, the Swallows' Stone, is a granite boulder in the hills above La Roca del Vallès, and its surface is covered with small carved hollows and other marks left by people in prehistory. Nobody knows exactly what they meant; such engraved rocks are found across Catalonia, and theories range from ritual offerings to maps of the stars. The rock sits among cork oaks and pines in the Serralada Litoral, the coastal range that separates the Vallès plain from the sea, and the walk to reach it is short and pleasant, through scented forest with views over the plain.
The hills around La Roca are full of prehistoric remains, including dolmens and the Cova de Vallmajor, a cave used in prehistoric times. The area is a popular place for walkers and cyclists from Barcelona, who come to escape the city at weekends. La Roca itself has a small old centre with a castle, though most visitors know it for the big designer outlet village on the edge of town.
The Vallès is an industrial and suburban region, with towns, factories and motorways, but it has a special place in the hearts of motorcyclists. Just a few kilometres south, at Montmeló, lies the Circuit de Barcelona-Catalunya, home of the Catalan MotoGP and the Spanish Formula One Grand Prix. On race weekends the whole area fills with fans, and the roads are packed. Granollers, the nearest large town, is a lively place with a market and a historic centre.
The riding nearby is excellent. To the north rises the Montseny massif, a natural park and biosphere reserve with beech and holm oak forests, and the roads that climb from the Vallès to the villages of Montseny and Viladrau and over the Coll de Sant Marçal are a joy, with endless bends, good surfaces and views. They are very popular with riders and cyclists at weekends, so take care. Closer at hand, the roads over the coastal range towards the Maresme and the sea are also good, with tight bends and views of the Mediterranean.
La Roca and Granollers have fuel, shops and restaurants. Try botifarra amb mongetes, sausage with white beans, or a plate of calçots in season, grilled spring onions dipped in romesco sauce. The weather is Mediterranean, with hot summers and mild winters.