Millions of Londoners still need to leave their homes for recreation, so it's a topical question.
It's also a very difficult question to answer because everything hangs on your definition of 'park'. You could only allow places called 'Something Park', but you'd then be ignoring Wimbledon Common, Primrose Hill and Blackheath which feels much too restrictive. You could allow any greenspace, but then you'd be allowing fields, cemeteries and scraps of turf on street corners which feels much too broad. What might feel most appropriate is anywhere you could take your toddler for a runaround or your dog for exercise, but answering this question is always going to be somewhat subjective.
What's required is a coherent recreational dataset covering the capital, so I've decided to go with the map provided by www.goparks.london which is a truly excellent resource. If they've coloured it green and named it then I've counted it (unless it's a cemetery, because that still doesn't quite feel right).
What's striking is how blessed London is with greenspace, indeed wherever you are there's almost certainly something within half a mile. It might be quite small or just a recreation ground, rather than a full-on Green Flag marvel, but it is still somewhere accessible to enjoy. I live very close to one small park, not far from several spots where I could walk a dog if I had one and a short walk from two of the best parks in the capital, so I'm doing fine. If you feel the need to tell us that you too live near a park, here's a comments box for that. comments
London was generally planned with greenspace in mind. so I've struggled to find areas of the capital where there isn't very much. The City is scattered with parklets. The West End boasts several massive Royal Parks. Ickenham may not be blessed with parks but it does border open country. The centre of the Park Royal Trading Estate might be half a mile from parkland but nobody really lives there. A green-free void between Abbey Wood and Bexleyheath is only grey on the map because its biggest park hasn't been coloured in. Balham, Putney and Walthamstow don't initially look promising, but drill down and the micro-greenspaces are indeed there.
So I'd like to suggest that London's biggest park-free expanse is in central Newham. Residential street after residential street after residential street, but nowhere to squat a dog.
Romford Road, which runs between Stratford and Ilford, defines one axis of this park-less space. Green Street, ironically, is the other. The junction where they meet, specifically just round the back of Forest Gate police station, is London's pole of parkland inaccessibility. From here it's just over half a mile to West Ham Park, just over half a mile to Plashet Park and just over half a mile to Wanstead Flats. 900 metres might not sound far, but the rest of London is so well blessed with greenspace that this singular spot loses out.
West Ham Park is glorious, a proper recreational jewel with tree-lined avenues, a bandstand, wild flower meadows, ornamental gardens and a variety of sports pitches. If it feels better maintained than your average park that's because it's owned not by Newham council but by the City of London. They stepped in when the Ham House estate was being sold off in the 1870s, undertaking to maintain the Park "forever" at its own expense. A century and a half later they're still looking after it, which helps explain why there were three gardeners grooming the borders in the Rose Garden before nine o'clock yesterday morning.
Plashet Park is smaller and a little more recent, opened in 1891, but still a resource you'd be happy to have on your doorstep. It's a shame the zoo in one corner closed down twenty years ago, and that the library in another corner has become a Register Office, but that's what council ownership gets you. As for Wanstead Flats this is technically the southernmost extent of Epping Forest, so again owned by the City of London. Which begs the question, why hasn't Newham council stepped up and provided better park provision around here?
Two reasons. One is that they can't. The local area consists of uninterrupted grids of Victorian terraced streets so there's nowhere practical to squeeze in another scrap of park. There aren't even any council estates where regeneration might have added a lawn or two. The other reason is that it's not Newham's fault, it's their predecessors. The county borough of West Ham was particularly slow to start creating public parks, its tardiness boosted because the City had stepped in and opened one first. The county borough of East Ham was a little keener, but didn't open a park this far north because a trio of cemeteries were in the way. I suspect it's no coincidence that Green Street, the spine of today's park-free zone, marks the former boundary between West Ham and East Ham.
A walk along Green Street today confirms it's all shops and houses. This is the very heart of London's Asian fashion offering, so you're more likely to come here for jewellery or sweet treats than to kick a football around. Up Boleyn Street I discovered the Upton Park Urban Oasis, a long narrow gap between two terraced houses repurposed as a desperately needed mini-garden. Ring Saleha if you want to hire the space and she'll unlock the gate. But it's not a park, nor anything approaching, so local children (and local dogs) still face a ten minute hike before they can find anywhere to exercise.
Ten minutes is nothing in the grand scheme of things, but it's exceptionally rare in London not to have a patch of public grass within a half mile radius. Unless you live on Green Street this is an impressively green city.