I sorted mail for city centre PO boxes, which tend to be firms and companies and such
One very fun discovery I did was that I learned about city centre expansion plans years ahead, I felt like a spy. In fact, I knew about it so many years ahead, that I begun to doubt it was gonna happen, like, just another plan that never comes to be, especially because it seemed so dramatic (shut down one of the main veins into the city, and transform a whole "shabby" stretch of city into green park with shopping streets, and opening instead an impressively long tunnel right underneath the same road)
By now, the tunnel is complete, so, it took time, but they're actually sticking to the plan