When did you last see a Ferris wheel? Sometimes called observation wheels, they're becoming fixtures in our cityscapes. It seems that any city that wants to ensure (0) attractions are on show to the world must have a beautifully designed Ferris wheel. (9) these wheels are usually intended to be temporary structures, more often than not they end (10) staying for a number of reasons, not least because they become so highly thought (11) by residents and visitors.

So why do cities want them? There's very (12) doubt that they create a novel focus, but there are several other reasons. They may be used (13) symbols of resurgence or a modern complement to the usual historic attractions tourists visit. They're also cheaper and quicker to build than most other major landmarks. Finally, seeing the success they've (14) in many places, cities may feel (15) sense of competition and be driven (16) build bigger and better versions.