Over the next few months I will be walking around the outskirts of Berlin, starting each walk where I finished the last, until I complete a loop of the edge of the city. These walks will be written up for a new book project, and here on Under a Grey Sky I will publish some postcards from along the way…

I walk away from the lake, up a narrow path that cuts along the bottom of a gorge formed by two steep wooded hills, the floor covered in soggy leaves. This sense of enclosure evaporates as I cross the street, following a path into an open expanse of fields separated by high pathway avenues. These are the Karolinenhöhe Rieselfelder, part of a series of sewage irrigation fields built in the second half of the 19th century to process the waste of the rapidly growing, industrialising city. These fields were set up outside Berlin’s limits back then, although by now the shifting boundaries outwards mean that most are contained within the outskirts. Some were in operation up until the 1980s, and are now either farmed or have been turned into nature reserves.

Here, just south of Spandau, the traces are more visible the other former sewage irrigation fields I have crossed during my walk. Mostly grassed over, there are tell-tale fixtures and fittings that speak to its previous function. Concrete canals and drainage ditches. Steep-sided basins. Cobbled service roads, lined with trees. I have been here before and yet it is just as strange as on the first visit. In a way it is emblematic of the outskirts as a whole. Neither city nor country. Aspects of both. An in-between place. An edgeland place.

Most of all it reminds me of the polders on the banks of the River Oder, right where Germany meets Poland. To get to the river and the coloured boundary posts the path drops down from one dyke, crosses the dry polder, and then rises up to a dyke on the other side. All the way across you are aware that you are walking in a place that perhaps you shouldn’t. A place created by humans where, at any moment, the water’s could rise and you would be literally up to your neck in it. At Karolinenhöhe I have a similar, uneasy-yet-illogical feeling, and I find my pace quickens as I follow the raised service road in a diagonal line towards the very edge of Berlin, on the other side.