Manchester has been on a provisional list for UNESCO World Heritage City on numerous occasions. However, since the 1996 bombing, local authorities have persisted on a course of economic evolution rather than prioritising the past. This economic evolution is perhaps best illustrated with the 558 foot (170 metres) Beetham Tower which instantly "torpedoed" any possibility of World Heritage City status according to one author. Despite this, areas perceived as internationally important in the Industrial Revolution, such as Castlefield and Ancoats, have been sympathetically redeveloped.