I've been living darn sarf (London and the Home Counties) for 25 years, and pretty much across the board the accent is pretty uniform, with a bit of give and take on just how strong the level of estuary is, depending on which side of London you live on.
So, when I was recently back in my home town of Liverpool, and I took a trip to St. Helens, it struck me just how different the accents are given such a short distance.
Six geographical miles between the 'Pool and St Helens and the accents are the the polar opposite. I like this about the north, and the south seems bland by comparison.
Anywhere else around the country you have accents change so much by travelling a few miles?