Ofcom, the regulator of the UK communications industries, has created a Google Map to show the speed of broadband throughout the UK.
Each county in the UK has been ranked on how they score on four broadband metrics; average sync speed, percentage getting less than 2Mbit/s, superfast broadband availability and broadband take up. The map displays as a basic heat map with each county coloured to show how they perform overall on each metric.
The map confirms what you already probably suspected. If you want superfast broadband then you are more likely to be lucky if you live in a big city. If you live in the Outer Hebrides then you are probably going to have make do with superslow broadband.
Ofcom - Broadband Speeds Map