- 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
Seoul, Kyoto, Beijing, Nanjing, Tokyo (capital + optionally direction)
Targovishte and Pazardzik (market, both in bulgaria)
Belgorod, Belgrade, Baicheng, Nicosia (white city)
Shumen and Bolivia (after guys named simon)
