this is a cool photo which highlights another significant factor that was used by the insurgents during the Uprising... the sewer system. most European cities at this time had very extensive sewer systems and were very well made/sturdy. Warsaw was no exception. these places were used for all kinds of purposes such as infilitration, relaying messages, transporting troops throughout city, establishing kill zones for germans who tried to penetrate them. you can see a squad of insurgents on the move here, probably just emerging on the left from underground the city.