Catching up with a few 3D crossviews taken earlier in the year. This first one is at St Pancras International Eurostar station en route to Paris (see what I did there...)
This is a crossview stereoscope meaning the image on the left is for your right eye and vice versa. To get the 3D effect you have to cross your eyes so the two images overlap, then sort of relax as it comes into focus. It can take a bit of practice at first, and doesn't work for everybody.