"Fossés" means ditches or "moat". The street is on the lower side of town (of course!).
The journalist asked me WHY I was interested in this scene; what inspired me. I said it was the shape of the window and the door, and the shutters that were over them. (The shutters ("volets") over the window were old broken wood, and the shutters over the door were rusty metal. Quite interesting!.