Mind your step is a street illusion at Sergels torg in Stockholm between 7-12 June 2011. Photographer Erik Johansson is the creator of this nice project. It is all in full-HD. Watch and enjoy. Watching the illusion from right position gave the impression of a 32 x 18 meter (105′ x 59′ feet) hole right down in the ground. For more go visit Alltelleringet.com.
And one video about how people react on this art.