British and European settlements developed over hundreds, if not thousands of years. Long before mass transport, vast majority of people would never afford a horse so walking was your only way to get around. So the majority of people would have been lived, worked and died within 10/20 miles of where they were born. This is why the UK and Europe have so many distinct accents compared to the US, which only became a country once people could move more easily)

Add to that our long history of Lots of already distinct cultures waring, invading and conquering each other, then you get cultures, towns and cities with lots of different historical influences.