The spiral minaret of the great mosque in Samarra, Iraq Once the largest mosques in the world, the great mosque of Samarra was all but destroyed in 1278. Only its outer wall and this minaret, which was originally covered in dark blue glass mosaic, are still standing. Photograph: De Agostini /Getty Images
A Robert Montgomery installation from WORDS IN THE CITY AT NIGHT. Echoing the Situationist concept of detournement, he hijacks advertising space (often illegally) by covering illuminated billboards with white on black posters that usurp the ad light parasitically. His texts are part poetry, part an inquiry into our collective unconscious, intended to be encountered by commuters who don't know the work is art and attempt to describe in the public arena what it feels to live now.