北城旧国南国旧城
[bĕi chéng jiù guó nán guó jiù chéng]
'Old Capital in the Northern City and Old City in the Southern Country' suggests reminiscing about old times and places that carry memories, usually indicating nostalgia for the past with specific locations attached, one from the North and the other from South. In Chinese culture, the north and south have unique historical significances, which could evoke particular sentiments.