2500 miles from London puts you somewhere in central Asia. I found the following route, which is just shy of that distance: https://www.distance.to/London/Samar

2500 miles from London puts you somewhere in central Asia. I found the following route, which is just shy of that distance: https://www.distance.to/London/Samara,Samara-Oblast,RUS https://www.distance.to/London/Samara,Samara-Oblast,RUS It would be an amazing trip, but it would involve crossing many borders and going through some fairly dodgy countries. I think there is a reasonable case that no sane person would do that on a whim.