"They crossed the Bulaq Bridge and the traffic got worse."

Boulaq is a district in Cairo, and makes up part of old Cairo.

An interesting source for reading about Old Cairo before both World Wars are the letters of Lady Duff-Gordon (1863-1935) who lived in Egypt for five years.

Blogger Dianabuja has picked out an Egyptian recipe for fattah from Lady Duff-Gordon's letters, which was made for her in the Boulaq district. (It sounds pretty tasty!)