The coast south of Barcelona has been a corridor since the Romans, and the Via Augusta, the main road from Rome to Hispania, ran along it. At Roda de Berà, a few kilometres down the coast, a freestanding triumphal arch from that road still stands, the Arc de Berà, and the Roman city of Tarraco, now Tarragona, is a short ride away with its amphitheatre above the sea, its circus and walls, all listed by UNESCO. So the hills behind Torredembarra and Altafulla sit in a landscape that already carries a lot of history, even before you get to the much older layers of paint on the rocks.
Shelters of this kind belong to the wider tradition of Mediterranean rock art on the Iberian Peninsula, listed by UNESCO in 1998. Access to such places is often restricted to protect the paintings, so contact the local museum or tourist office before going, and expect to walk on rough paths. Do not touch or mark the walls.
The seaside towns are the pleasant part. Altafulla has a walled medieval village on a hill with a castle, white houses and narrow lanes, and below it a wide, sandy beach. The Roman villa of Els Munts, with its mosaics and baths, lies close by and belongs to the Tarraco World Heritage group. Torredembarra, with about 15,000 people six kilometres away, is the larger town, with fuel stations, supermarkets and a good beach promenade, and it is the sensible place to fill the tank.
The riding is easy rather than exciting. The old N-340 runs close to the coast and is busy in summer, while the inland roads climb into small hills of pine and carob with gentle bends and good views of the sea. Spring and autumn are lovely, with warm days and fewer visitors, and the Mediterranean is warm enough for swimming into October. Try a plate of calçots in late winter, spring onions grilled over fire and dipped in romesco sauce, and a glass of cava from the Penedès, which lies just inland.