Xray has nothing to do with geography though. However you could have an answer that strays slightly from starting with an 'x' to one that contains an 'x'. How about 'EXeter'. When you say it, it certainly sounds like it starts with an 'x' and it's a well known enough city in its own right - i.e. it's the county town of Devon.
fear of things beyond the Channel - xenophobia;
element jointly discovered by Scottish and English chemists - Xenon;
Medical procedure invented in Britain - X Ray
and so on...