Last week I finished visiting every postcode district in London. But, as I explained, that was just the 244 postcode districts with addresses. Another five merely contain "addressable locations", like ponds, bridges and pylons, and my rules said I didn't have to go to those. But a question mark arose over WD19 where one particular electricity substation in outer London can only be accessed from Hertfordshire, and although it appears to have the right postcode it might not be current, and basically does it marginally count or doesn't it? So I decided the easiest thing to do was to go anyway, then it didn't matter if it counted or not because I'd definitely been. And then I decided to go to the other four as well just to put the entire project unequivocally to bed.
Here then are my reports from London's five most marginal postcode districts, where absolutely nobody lives, in a lengthy blogpost that's as peripheral as peripheral gets. [map]
This overlap amounts to half a footpath and probably the field nextdoor, in the dangly bulge of Kingston that pokes out like a tongue into Surrey. To get here take the train to Chessington South, or better still the K4 bus to Mansfield Park, and locate the alleyway off Merritt Gardens with the amateurish Pooh Bear sign. This is not the footpath we seek, more a suburban escape valve leading past thickety hedges, electric fences and flowery paddocks labelled Do Not Feed The Horses. But eventually you'll reach a fingerposted junction and this, or some adjacent invisible object with the appropriate designation, is one of the two addressable objects in London to have a KT10 postcode.
The other is 200m up the path with the warning triangle, a shady oaken bridleway with dollops of dried manure confirming yes, you should indeed slow down and watch for horses. Through one fence is what was once RAF Chessington, first a base for barrage balloons and later a medical rehabilitation unit, most of which has been turned into that housing estate we were on earlier. Across the other fence is a hay meadow which on my visit looked like it had just been cut and which was alive with a bountiful bustle of butterflies - the longer I looked the more I saw. And beyond that is the A3 Esher Bypass, a dual carriageway which has been providing all the background noise in the vicinity since 1976.
A separate footpath winds west towards the A3, flipping into Surrey just as it descends into Stygian gloom to pass beneath the roadway through a grimly engineered subway. That leads to the village of Claygate and proper KT10, whereas the path in the London sliver bends back past nettles and dogroses before rapidly hitting KT9. It's more Hook than Chessington around here if you're keeping notes. A bike-proof gate then leads into a small park formed from RAF remnants, whereas if you continue along the path you may meet a member of staff from the nearby primary school grabbing an offduty cigarette and wondering what on earth anyone else is doing here. And if none of this is ringing any bells whatsoever I'm not surprised because nobody wanders into London KT10 without good reason.
In sharp contrast let's shift to the estuarine Thames, specifically the marshy nomansland between Rainham and Purfleet. Nobody lives within a mile of here so it's frankly strange that any postcodes were ever allocated, but one drainage pond on the Havering side of the boundary has been designated RM19 1SZ and that's what brought me here. If you've ever walked the last section of the London Loop you'll know how bleakly remote it is round here but that particular route hugs the waterfront so you won't quite have seen the pond inland. Instead you need to follow Coldharbour Lane, the ancient track since converted into a lengthy curve around two sides of a massive landfill site plied only by a steady stream of trucks and lorries. The adjacent footpath passes numerous numbered ventilation outlets, crosses the main road at the Rainham Silt Lagoons, dodges the turnoff for "Landfill, Compost and Road Sweepings" and plods on towards the Veolia Plastics Recycling Centre. If it sounds like I'm not selling the experience, this is deliberate.
The path eventually starts to climb, admittedly only gradually but in an estuarine setting that's all you need for a sweeping view across the marshes. Long creeky fingers spread across a landscape of long grasses dotted by the occasional bush and stretching off to a line of pylons on the horizon. It's a marvellous habitat for birdlife, especially when waterfowl are migrating, but their song will provide the backdrop to your visit at any time of year. At the top of the slope a small path breaks away to a proper viewpoint with a bench, though if you sit down the best of the vista diminishes so it's probably best used for resting a rucksack or a long lens camera. And hurrah, this spot is precisely above the pond with the RM19 postcode, and ooh look a trampled track descends almost to the water's edge, and it turns out this is an addressable object you can actually address.
The mound here isn't natural, it's the edge of a shelf of landfill established here when William Cunis established a dredging company at Coldharbour Point in 1906. Gravel and ballast headed upriver to assist with construction works and in its place came rubble and ash from burning coal mixed with food waste and other organic matter. Where that slope stops The Great Salting begins, a sprawling marsh on the line of the former Wennington Creek, and beyond that the public half of the RSPB reserve at Rainham Marshes. But that's in Thurrock, the edge of the capital being an invisible line weaving down to the river's edge at Aveley Bay (which is the 'beach' I mentioned and pictured in Sunday's post). It's a right trek to get to but for those of an ornithological bent, usually worth the effort.
Next we switch to the diametrically opposite side of London along the Colne Valley between Hillingdon and Bucks. The edge of the capital follows the river, or at least some braid of it, all the way from Rickmansworth to the M4 and here near Yiewsley the Royal Mail's boundary very nearly matches. But postcode district SL0 bleeds just across the Colne to three bits of infrastructure on the London side, all of which by chance are part of London Loop section 11. The first is on the Slough Arm of the Grand Union Canal, a lengthy but serene dead end that now hosts anglers, ramblers and a pair of quite angry-looking swans. Just before the border comes a iron footbridge, originally for carts, which carries an old track called Trout Lane across the water. This offers an excellent view down the channel, if what you like is arrow-straight algae, and is scrawled with minor graffiti including the frankly baffling Capitalism Is Pog.
Trout Lane's lovely at this time of year, a cyclepath bordered by buttercups and butterflies, and before long leads to the car park which is the second addressable object in London SL0. It's only small so you may not get a space, but if you're a particularly lazy parent you need only to walk a few steps to the river where your children can paddle excitedly in the shallow water. Officially this is the car park for Little Britain Lake, a body of water supposedly named because it's a similar shape to the British Isles as seen from the air, but in fact the local hamlet had that name long before its fields were flooded so that's an urban myth.
Meanwhile that paddling spot is actually a former ford on a country lane between Yiewsley and Iver, named on one side as Ford Road and on the other as Packetboat Lane. Those on foot were instead diverted to a convenient footbridge a short distance upstream... and that's addressable object number three (but only eastern half because the county changes midstream). It may be SL0 but there's not quite zero here, not quite.
SL3 is the largest postcode district to overlap Greater London without containing any buildings or houses. Two reasons. The first is that it's not advisable to build on the floodplain of the Colne, which is where we now are, being a bit further downstream than the previous SL0. And the second is that the M25 didn't exist when postcode districts came into existence a century ago but the Greater London boundary has subsequently shifted from the river to the motorway. This means several meadows that were once just outside the capital are now just inside, and they tend to have become Ballardian landscapes adjacent to sliproads, hard shoulders and concrete viaducts.
Here's just one of the 14 addressable locations, namely the point where the old Bath Road crosses the eleven lane span of the M25. It's the only place in today's post I haven't visited in the last week because I accidentally went last month on my trip to the Heathrow Biodiversity Site. Thankfully I took this photo as a plane thundered across on final approach, little realising that the far side of the bridge would tick off one of my questionable postcode boxes. A particularly strange fact is that SL is the only postcode area to enter Greater London without anybody living in the overlap, i.e. a total technicality, and that's with two different postcode districts crossing the line.
Finally to Hertfordshire and the stripe of Green Belt that separates Hatch End from South Oxhey. It's quite a definitive break with no housing or indeed roads to span the grassy gap, just a few footpaths (and the London to Manchester mainline railway). The easiest way in from the London side is via the Sylvia Avenue Open Space, a scrubby patch of barbecue-friendly woodland serving residents at the most isolated tip of Hatch End. Aim for the electricity pylon on the far side of the meadow, indeed it might be the pylon that's the crucial addressable object or it might be the gate alongside because that's slap bang on the border.
The pylon is one of several feeding into Hatch End Grid Substation, the infrastructural anomaly which triggered my need to visit WD19. Apparently it can transform power from 132kV to 33kV to 11kV as required, and probably back again, and is located liminally on the inside edge of the capital. The big clue is the fact it's named after Hatch End, despite abutting South Oxhey and only being accessible from South Oxhey which is how it got its WD19 postcode. But if you check UPRN 10025291166 the subtext says "This appears to be a deprecated UPRN. It was not included in the most recent OS Open UPRN database update." which suggests it isn't in WD19 6XA any more, indeed it may no longer be a functional place. I had to walk round via the mean streets of South Oxhey to reach its securely locked gate, but walk round I did and got no further clues from the exterior.
The only other accessible addressable location is a complex junction of multiple footpaths a tad to the west. One links to the power station, one to Heysham Drive and one crosses a sleepy paddock rife with windblown grasses. The other two are part of London Loop section 14, first sweeping in from Oxhey Woods across a dung-splattered field and then bearing off towards the elite breeding zone of Pinnerwood Stud. The aspect facing the greatest immediate threat is the sleepy paddock which Watford Community Housing Trust plan to transform into an estate of 53 homes, all either shared ownership or affordable rented. Local owner occupiers are aghast, having assumed that their gardens backed onto protected green belt in perpetuity, but apparently "the Site will achieve a 31.21% biodiversity net gain" because even greenwash comes to two decimal places these days.
...and with my trip to WD19 yesterday that's all of London's 249 postcode districts visited, even if you include the five districts where nobody lives. To be on the safe side I also dropped in on KT7, i.e. Thames Ditton, which is entirely outside London apart from three postcodes based at the main sorting office in Kingston. I did say non-geographic postcode districts don't count, and I stick by that, but KT7 appears to be the only Home Counties district which includes non-geographic postcodes inside London so I ventured up to the Customer Service Point in Hogsmill Lane anyway.
Belt and braces, better safe than sorry, no arguments, no ambiguity, done the lot. And not just all 250 postcode districts this year but all 250 in six months flat. I stick by my contention that nobody else has ever done this, not ever, the spread of minor peripheral overlaps being far too unlikely to achieve by chance.
It sounded such a simple idea when I started tallying back in January, but my word it's taken me to the extremes. Let us never speak of it again.
