My father in law pulled up beside some holla back in the 1970's to ask the locals if he was on the road to Richmond. The local responded to the enquiry where this road led, and this is legit, "my dear boy, this road leads to everywhere"!
https://en.wikipedia.org/wiki/Prudhoe_Bay,_Alaska
https://en.wikipedia.org/wiki/Yaviza
Google Maps says it's about a 104-hour drive (without breaks of any kind).
You could also think about borders that are closed. Like if you want to go from Haifa to Beirut, the shortest legal route goes through Jordan and Syria!
Or with the Darien Gap, people asking about how to drive from Panama City to Cartagena might be surprised -- you actually can't get there from there (by road).