With "Prosperity over Poverty: Culture and Tourism for New Vitality of Silk Road" as its theme, the 4th Silk Road (Dunhuang) International Cultural Expo and the 9th Dunhuang Tour-Silk Road International Tourism Festival were unveiled on Tuesday. The event will run for 40 days and closes on Sept 5. Over 30 cultural activities will be held across 14 cities in Gansu province.