I was putting this cover into my weekly ebay sales, and I thought, "This would make an interesting discussion".
I invite others to join this thread with examples to add to the theme.
1909 Great Britain to Manchuria in 16 days via Trans-Siberian Railroad
Dairen (under Japanese control after the Sino-Russian War of 1905) was renamed Dalian under the Chinese. It is just across the gulf, to the east, of Tianjin on this map (near Beijing).
I think the secret to this kind of rapid movement is to just keep it moving, rather than get a letter held up in some massive sorting center. It almost doesn't matter the speed of the movement, it just has to keep moving in the right direction.