Central London is well-blessed with stations, for which we must thank the Victorians and Edwardians. Wherever you are in Zone 1, there's very probably at least one tube or railway station within half a mile of where you're standing. But not quite everywhere is close to one, so today's challenge is to locate Zone 1's accessibility coldspot.
My first problem is that buildings, gardens and even the River Thames sometimes get in the way of where you want to go. To simplify things, I've decided to always measure distances in a straight line, even though it might not be possible to walk direct. This is helpful, because it means I can reuse the special 'Nearest station' map Ollie made for us earlier in the year. Wherever finally ends up being "the furthest from a station", I know it must be at one of the points where the boundary lines on Ollie's map meet.
My second problem is that Zone 1 isn't well defined. I know which stations are in Zone 1, or on the boundary, but today's question is about the areas inbetween which are much woollier. Everything within the Circle line is obviously in Zone 1, but the zone's extent is particularly unclear south of the river and nudging into the East End. My definition is going to be whether I think a station built at the point in question would likely be in Zone 1 or not. That's a bit subjective, but let's run through the contenders, firstly four "almost certainly yes"s and then two "most probably not"s.
The outright winner, the spot in Zone 1 furthest from a station, must surely lie within one of central London's largest parks. Hyde Park and Kensington Gardens cover over 600 acres, and are entirely station-free, so let's look there. The Central line runs along the northern perimeter, with stations at Queensway, Lancaster Gate and Marble Arch, so my target should be somewhere nearer the opposite edge. It turns out that the "most remote" spot in Zone 1 is beside the Albert Memorial, in fact on the northern edge of the square surrounding it. From here Lancaster Gate, Gloucester Road and South Kensington are each almost precisely 1km away. I checked with Citymapper and it advised me of a 16 minute walk to each. Those who live elsewhere in the country might think 16 minutes is peanuts, but in central London it's about as far as you can get.
Embassy Gardens is the new luxury housing development going up around the US Embassy, on the southern side of the Thames. It may not surprise you to hear that the "most remote" spot hereabouts is the Chancery Building, the estate's lowlier shared ownership block. This lies back from Nine Elms Lane, beyond Waitrose, in what'll be a gloomy corner once all the surrounding towers shoot up and block out the sun. At present it's almost a kilometre from Battersea Park, Vauxhall and Pimlico stations - the latter impossible to reach direct because of the river. In a couple of years this spot will be approximately midway between two stations on the Northern line extension - Nine Elms and Battersea Power Station - so considerably better connected. It's Boris's pledge to place both of these in Zone 1 which allows me to confirm that Embassy Gardens deserves its place in my list.
My next inaccessible backwater lies along the main road hugging the north bank of the Thames between Battersea Bridge and Vauxhall Bridge. Specifically it's at the point where the mainline railway out of Victoria heads south across the river, beside the Grosvenor Road Carriage Sidings, almost immediately opposite Battersea Power Station. From 1867 to 1911 there was a station right here, unsurprisingly named Grosvenor Road, and its subsequent disappearance helps to explain why this spot became a hole in the existing network. Pimlico station on the Victoria line helped plug the gap in 1972, confirming we're in zone 1, but is still 900m away. The other stations we're 900m from are Victoria, Sloane Square and Battersea Park, each approximately 15 minutes walk away according to Citymapper.
Crossing town, here's an unexpectedly badly-connected spot in a proper built-up area. It's on the huge Royal Mail site at Mount Pleasant, specifically the undeveloped bit alongside Farringdon Road, close to the junction with Calthorpe Street. Five stations are almost equidistant, namely King's Cross, Angel, Farringdon, Chancery Lane and Russell Square, each approximately 13 minutes walk away according to Citymapper. What's ironic is that the Underground passes almost directly underneath, and also that this was London's very first Underground line. The Metropolitan Railway failed to build a station here in 1863, most likely because at the time this was the site of the notorious Coldbath Fields Prison, upon which the Post Office mail centre would be built 25 years later. Alas nobody ever came back to fill in the gap by adding Mount Pleasant station, and today's economics dictate they never will, however useful it might be.
The Chelsea Embankment never got a tube service and remains a long way from any stations. The District line runs annoyingly far north, via South Kensington and Sloane Square, and the 9-year-old Overground station at Imperial Wharf is a similar distance to the west. I checked with Citymapper, and it advised me of a 20 minute walk to each. Most of the people who live in the smart houses along Cheyne Walk have a car, or would be happy to hail an Uber, so probably don't mind living so far from a station. It's no coincidence that Crossrail 2 is intended to bring Chelsea its very first rail connection, a little further north on the Kings Road. I'm just not quite convinced that this particular spot alongside the Albert Bridge really is in Zone 1, so it probably doesn't deserve to be on my list.
As another central expanse of green space, it's no surprise that Regent's Park contains another accessibility coldspot. The point furthest from any station lies amid the sports pitches on the northern side of the park, very close to the artificial hill of The Hub with its changing rooms and cafe. It's also very close to London Zoo, specifically the Reptile House, which helps to explain why the zoo is always a bit of a schlep for tourists to reach. The closest stations to the point in question are St John's Wood, Camden Town and Baker Street... although two of these are in zone 2. That's also the case for Mornington Crescent station, which lies almost due east, which again suggests that this particular spot couldn't genuinely be described as zone 1.