This is art as buried treasure. Not all art craves attention, some of it hides in the secret places. Some of it is buried treasure, out in the urban wilderness, left scattered in empty rooms of derelict buildings like strange markings left by an unknown tribe. These works are gifts given only to the occasional explorer, found in abandoned factories, warehouses, industrial sites and deconsecrated churches. This is art you have to earn by leaving the designated areas and heading out past the No Entry signs of the urban environment. A diverse range of artists find themselves attracted to these twilight zones and in recent years something of a movement has come to light, huddled around the idea of urban decay and abandonment as the ultimate canvas. This burning curiosity to see what is behind the fence exists to a greater or lesser degree in most people, but for some it is irresistible. The intervention of street art in these places ranges from walled spaces saturated with layer upon layer of tagging to strange little installations intended to mess with your head. Surreal comments scrawled on windows can be found alongside hidden characters, placed to surprise you as you turn a corner. Is there some universal human urge to say 'I was here'?