[LorenPechtel]

Yup. There used to be "tour" groups that operated Katmandu to London. Sort of like this bus service but expecting to spend time in the cities it passed through. In 1975 I (with my parents) did what was supposed to be Delhi to Tehran, but we ended up leaving in Shiraz because of a breakdown, it was going to take too long to fix.

I've also done part of the Johannesburg to London route. Rougher, we were in a truck fitted out for passengers and most nights were in tents. Again, breakdowns, we were forced to leave before crossing the Sahara.

Neither route would be sane to do these days. Nor am I aware of any other such long route that's still sane. Such overland travel takes longer than flying by air but you see so much more of what you're passing through.