The ochre town of Sóller lies in a valley surrounded by the grey-green hills of the Serra de Tramuntana. The Arabs saw the potential of the valley, known as the Vall d’Or (Golden Valley), and accounts of orange and lemon groves, watered from sources in the hills, date to the 13th century. The citrus-fruit export market laid the foundations for the great wealth of the town, reflected in its railway line to Palma (1912), tram line to the Port de Sóller (1913) and the grand merchant houses that throng the town, such as those strung out along Gran Via and Carrer de Sa Lluna.