Castelldefels is where Barcelona's beaches run out and the mountains begin. The town sits on a long flat stretch of sand south-west of the city, with the Garraf massif rising steeply behind it, a rough block of limestone, scrub and pine that tumbles into the sea. A hilltop castle, first recorded in the eleventh century, overlooks the town, and the coast road, the C-31, runs along the shore toward Sitges through tunnels and above cliffs.
The label points to Tibidabo, the mountain behind Barcelona on the other side of the city, about twenty kilometres to the north-east, topped by a church and an old amusement park with a Ferris wheel and views across the whole city. The ride has crossed the whole of Barcelona, from that summit to the south-west, so this is the end of a long loop. The riding in the Garraf is the sort that suits a dawn start, with tight bends, steep climbs and wide views over the Mediterranean, and the Garraf Natural Park has gravel tracks and winding lanes through scrub that smells of thyme and rosemary.
The surrounding towns are practical rather than pretty. Gavà, with about forty-six thousand people, is a working town with a long beach and a mining museum, and nearby are archaeological sites from the Neolithic, when people dug galleries for a green mineral called variscite. Begues, higher up in the hills, is a small village with a more rural air, and a good place for a coffee. In summer, heat is intense, and in dry years fire danger can close some tracks.
Fuel, food and rooms are no trouble in Castelldefels, which has more than sixty thousand people, and beach restaurants serve rice with seafood and grilled fish. Weekend traffic on the coast road can be heavy, particularly on summer evenings, when everyone heads home from the beach. The best months are April to June and September to October, when the air is warm and the crowds thinner.