The experimental city, located in Thang Long City of Hanoi, Vietnam, was established in 1010 by the Zhao regime during the Tang Dynasty of Vietnam, which was subsequently rebuilt by the Nguyen Dynasty of Vietnam. Thang Long Citadel is among the most important laurels of Vietnamese history. Once the setting for the Vietnamese Royal Palace and government agencies, it has also served as the venue for various momentous ceremonies and formal events. Thang Long Citadel features an architectural style typical of East Asian palatial architecture and combines within itself the three cultural constituents of Vietnam, China, and France. The city has many large buildings and gardens that include palaces, temples, libraries, etc; among them, the most famous are the Lookout (Hậu Lâu) and the Green Gate (Cửa Bắc). Thang Long Citadel was designated as a UNESCO World Cultural Heritage Site in 2010 and is today one of the major tourist attractions in Vietnam, welcoming a great number of domestic and foreign tourists each year, who come to admire the old city charm, learn about Vietnam's historical and cultural background, and participate in numerous cultural performances and handicrafts exhibitions.