I grew up not that far from Kidderminster so knew that but wouldn't have known where Herne Bay was. I remember being asked, when living in Leeds and mentioning getting the train back home to Shrewsbury being frequently asked if I had to go via London.
I don't expect people to know where it is though. I was surprised though when I wasi n California that people there had heard of Shropshire, the most common reply to saying where I'm from I got though was randomly about sheep!
A random one was in a Starbucks in Toronto. The nice guy serving me asked if he could try and guess where I was from from my accent and guessed West Midlands. I was so impressed considering I've not lived there for about 15 years and lived in a number of other places with far stronger accents and never had a strong accent anyway!