The jet-set strip of Sardinia, Costa Smeralda is a six-mile (10km) stretch of coastline between the gulfs of Cugnana and Arzachena on the island's northeast coast, which has become a developer's paradise and extremely popular with holidaymakers. Legend has it that a fabulously wealthy consortium of businessmen first exploited this beautiful wild coastal strip in the 1960s, backed by the Aga Khan. Today the local villages and towns around Costa Smeralda have become discreet up-market resorts crammed with private villas, luxurious holiday villages, contrived Mediterranean-style shopping malls, low-rise high-priced hotels and huge yachting marinas packed with gleaming yachts. The main town of the area is Porto Cervo, a crime and litter-free playground of the rich with its ranks of pale pink and red villas climbing the hill from the busy marina. The other favourite retreat for celebrities is the town of Porto Rotondo, situated on a natural cove about 10 miles (16km) from Olbia, site of the international airport. The town offers a wealth of beaches, nightclubs, bars and restaurants, most clustered around its Piazza San Marco, and the marina. The main attractions of the Costa Smeralda are the numerous sequestered beaches, none signposted, which can be discovered simply by following a dirt track down towards the sea. Among the most scenic are Cappriccioli, Rena Bianca and Liscia Ruja, all south of Porto Cervo.