In the north-east of the island, Olbia stands out above all as “the” city, the economy engine of Sardinia – with its airport and road network. Here, you can stop to admire its Romanesque San Simplicio basilica, the Roman aqueduct, the 18th-century houses and, of course, the open-air theatre. But, above all, Olbia is the southern tip of the Costa Smeralda, the Emerald Coast that extends over 50 kilometres of seaside, where the windswept granite mountains of Gallura descend into the emerald coves and bays that punctuate the coast, such as Capriccioli, Cala di Volpe and Spiaggia del Principe. The region, extending up to Palau further north, also has its fair share of superb secluded coves.