Core Points - The main event of the Cultural and Natural Heritage Day is being held in Changsha, which is described as a "museum without walls" [1][4] - Changsha is recognized as one of the first national historical and cultural cities in China, with a history dating back 150,000 to 200,000 years [4][5] - The city features numerous museums and cultural sites, showcasing a rich collection of historical artifacts and treasures [10][11] Summary by Categories Cultural Significance - Changsha is referred to as a "museum without walls," highlighting its extensive cultural heritage and historical significance [4][10] - The city has witnessed significant historical events from various dynasties, including the Qin, Han, Tang, and Song [4][5] Museums and Exhibitions - There are 32 state-owned museums and 20 private museums in Changsha, collectively housing numerous national treasures [10] - The article lists several must-see national treasures, including the "Su Sha Dan Yi" and the "T-shaped Silk Painting," which reflect ancient wisdom and cultural beliefs [11][13] Upcoming Exhibitions - Multiple special exhibitions are organized during the Cultural and Natural Heritage Day, including "Endless Yangtze River - The Yangtze and Chinese Civilization Exhibition" and "Searching for Ancient States in the Records of History" [39][41] - These exhibitions are free to the public and feature significant artifacts from various ancient cultures, enhancing the cultural experience for visitors [39][41][44]