I now understand how John Speke felt when he discovered Lake Victoria.
Who would know that such a magnificent body of water would have lain hidden and untouched in N London?
The cycle underpass that forms part of the off road "facility" for cyclists to bypass Meridian Way was the location of my discovery. It may be strange to think that such a geographic feature may lay undisturbed in such a populous region, but it all makes sense when I realise that I am the only person stupid enough to actually use this route on a cycle. The water feature is completely obscured to the vast majority of the sensible population using their cars.
It was significantly deeper than I expected when I rode through.
Since I was the first to encounter it, I wish to name it Lake Grumpy - home of the discarded plastic bag and slight smell of excrement.
Coming back, I used Meridian Way. Which is almost as deeply unpleasant as wading through this lake of gunk, as the 40mph speed limit is widely disregarded. Well, enforcing the law would be a war on the motorist wouldn't it?