Google Earth

[den]

While mucking around with Google Earth, I thought I'd have a look for Griffin Park, the home of Brentford FC and my favourite UK football team. I enterd "brentford, england" into the search and hit enter, as you do. Google Earth zoomed in to Brentford, West London, and... what the hell is that? Just west of Brentford, beside the M4, and a whacking great black rectangle. It's obviously hiding something, but the huge black blank is an enourmous "NOTHING TO SEE HERE MOVE ALONG!" sign.

Now I want to know what's there.