From time to time you discover something totally remarkable on the web. Today’s discovery (thanks to this tweet from @ChristianWolmar) is Sleepycity – is a tremendous and rather freakish collection of pictures from transport systems in Europe, most notably the Paris Métro, but there are also London pics and images from bridges and other structures. Their post ‘Demolition of the Paris Metro‘ is a summary of what they’ve found, including details of hidden stations, how they were reached, and discoveries of all kinds of oddities including 1940s advertising and abandoned, graffitied trains in tunnels. Take some time to browse around and be astounded by the daring of these guys, and marvel at the quality of the photography.