Overview: Historian and writer Dan Cruickshank celebrates the creative force of architecture as he explores the world's greatest cities, buildings and monuments. Dan looks at buildings that evoke the image of heaven across religions and cultures, travelling to Egypt's Sinai desert, China's Hanging Temple, and Turkey's Suleymaniye Mosque, a building that evokes the gates of paradise. Finally Dan loses himself in the boisterous holy town of Sri Ranganthaswamy, a place sacred to the Hindu religion.