Jandia, Spain - Some people smile when they see them, others find them annoyingly bourgeois and simply shake their head. Whatever reactions they provoke, the round rock shelters on the southern beaches of Fuerteventura, one of Spain's Canary Islands , are an integral part of many people's holidays and a second lodging for more than a few tourists. Roofless, about 2.5 metres in diameter, and fashioned from local volcanic rock, the shelters offer protection from the wind in addition to privacy for those inside them, most of whom prefer to sunbathe in the nude.