- Cartagena and Naples ("New City")
- Des Moines and Munich ("Monks")
- Neuchâtel and Newcastle (I think this one is obvious)
A near miss: Trois-Rivières and Sichuan (3.5±0.5 rivers)
There must be more of these, please add your own
OK I had to look this one up and it's close to true! Vancouver is named after a guy whose ancestors were called van Coevorden, Coevorden being a town in the Netherlands whose name means for "cow-ford". So Oxford and Coevorden are synonyms (unless we quibble about "cow" vs "ox"), and Vancouver is more like "from cow ford".
Also, in English a ford is very different from a fjord—a ford is part of a river so shallow you can wade across, and a fjord is an ocean inlet with steep cliffs—although they do apparently share the same root with each other as well as "firth" and (more distantly) "port".
