What is the longest distance on mainland UK, measured from John O'Groats at the northernmost point of Scotland to Land's End in the southwestern corner of England?

Okay, let's talk about the distance between John O'Groats and Land's End. This is a classic measure of the length of Great Britain, and it's about 870 miles. To put that in perspective, think about driving from the very top of Scotland, through all the amazing scenery of the Highlands, down through England, past the Lake District, through the Midlands, across the southwest, all the way to the tip of Cornwall. It's a significant journey! The other distances are way off. 460 miles would only get you part of the way through Scotland, and the other options are exaggerations. This end-to-end journey is often undertaken by charities to raise money, and it's a great way to see the diversity of the British landscape. So, remember 870 miles for that iconic north-south stretch.
Imagine a cross-country journey exploring the breadth and beauty of UK from the chilly north to the mild southwest.