It's still possible, if you drive, to get a glimpse of some of the grandiose and palatial villas built at the beginning of the 20th century, when the Cote d'Azur was considered the most beautiful, the most fashionable and the most affluent resort in Europe. Nicholas Merchant talks about some of the houses built then, including the Villa Ephrussi de Rothschild and the Parc St Bernard.