'Urban Explorers'see Belgium as a land of ruins and come from all over the world to photograph dilapidated and abandoned buildings.Architects have coined a term for uncontrolled building driven by speculation, a lack of urban planning, and a lack of regulation: It is Brusselization. As new buildings go up in seemingly random fashion, a lot of old ones are left to rot. The country's architectural heritage is at stake. But the Urban Explorers are having a field day.