sevenmaplinks
If you've walked the Capital Ring and completed the London Loop then you might be up for a bigger challenge. How about the London Green Belt Way, which orbits the Green Belt for 220 miles at approximately M25 distance. You'll not find it signposted on the ground, this isn't yet an official project, but it has been around since 1995. [a relay race runs the course each year, so stick 17th/18th May 2014 in your diary now]
It's rare to see a map of London's surface, that's elevation and waterways, because usually this level of detail is stripped away. David Fisher has put together a map of both, that's contours and rivers, even including those elusive lost rivers. Apparently he's based their courses on my research, which may not be 100% kosher, but it's instructive to see how the Fleet, Westbourne etc fit together. See the full size map here. [If you live in the floodable low bits of town, maybe you should move to Hampstead or Crystal Palace]
Riding a bike is always risky, be that in London or beyond. Adrian, the author of icycleliverpool, has assembled a UK-wide map of Cyclist Fatalities 1985 – 2013 with one pin for each sad statistic over that time. Zoom in to identify the blackspots near you. [red pins for male casualties, blue for female]
Do you love hanging out with friends on Hampstead Heath, but find it very difficult to locate each other over the vast expanse of land? If so, Vivienne may have come up with the answer. She's devised an overlay map of coded squares, called Park Grid, so that “instead of saying ‘I am just past the dog pond on the east side of the park’ you can just say ‘I’m in J9′”. Vivienne hopes that Park Grid will make meeting up on the Heath that much easier, "so you can spend more time enjoying and less time finding." [I suspect there's more than one target audience for this]
For an at-a-glance look at where in the UK trains aren't running properly, try the Realtime trains Heatmap. Coloured contours glow wherever trains aren't running to time, with red areas indicating the worst delays. [that's National Rail trains only, not the Underground]
One of the more useful apps I've stuck on my young smartphone is Maps With Me. That's the free version, obviously, not the expensive upgrade. Download maps of anywhere in the world - I picked the whole of England - then store these on your phone for when there's no network signal. Admittedly 'Maps With Me Lite' doesn't allow you to search or create bookmarks, but who needs those when you can whizz around the map manually? [terribly useful when I was out of range on the Kent coast earlier this week]
Meanwhile, I'm still convinced that the very finest London transport app is Citymapper. Live info on buses, including what's going where from which stop when. Live info on trains, including tubes and National Rail, even which platform each service is going from. Plus journey planning, plus disruptions, plus how precisely to walk to the nearest station and how long it'll take, plus how many spaces there are at the cycle hire stand down the road. Citymapper's saved me hours of unnecessary waiting around. [and somehow it's still free to download]