Which city lore for PC street urchin background?

[Flambe]

I have a player who is joining my Age of Ashes game. We have finished book 1. He chose street urchin background which provides a specific city lore. Which city should I recommend he choose?

[zimmerwald1915]

Katapesh or Kintargo for something that'll be useful to the AP. In that order. Promise would also be useful in the AP, but being a utopian planned community probably doesn't permit street urchins.