Viewfinder competition: win a £200 hotel voucher

It began as an eighth-century Pomeranian stronghold where a castle still stands today. Photograph: PR

Situated along a lake, a river and on several islands, it is a major seaport. Photograph: PR

This industrial hub’s abundance of green areas and wide avenues were built by a man more famous for his grand designs on a far grander city. Name the city. Photograph: PR

This week’s winner will receive a £200 voucher from Hotels.com which can be used at more than 200,000 places to stay across the world, from quirky B&Bs and family boltholes to boutique hotels. Hotels.com customers can get a night free for every 10 stayed with its rewards scheme.
Email your answer by Thursday, 20 June 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 Reykjavik, Iceland. The winner was Geraldine McCambridge Foster of Yateley, Hampshire. Photograph: PR