Viewfinder competition: win a £150 hotel voucher

Crowds flock to this island’s aquarium, the largest in Asia, to watch the antics of a bionic dolphin… Photograph: Getty Images/Flickr RF

… its people are similarly frisky, holding world records for longevity and healthy ageing… Photograph: Alamy

…the site of a major battle in the second world war, it is ringed with sandy white beaches and dotted with ruined castles. Name the island. Photograph: Miko Walczuk Photography/Getty Images/Flickr RF

This week’s winner will receive a £150 voucher from Hotels.com which can be used at more than 120,000 places to stay across the world, from quirky B&Bs and family bolt holes to boutique hotels. Hotels.com customers can get a night free for every 10 stayed with its rewards scheme. Email your answer by Thursday 13 January to viewfinder@observer.co.uk or send a postcard, with address and phone number, to Viewfinder, The Observer, Kings Place, 90 York Way, London N1 9GU. ■ Last week’s answer was La Réunion in the Indian Ocean. The winner was Joanne Bloor from Prenton, Merseyside. Photograph: David Parker/Alamy