The Imperial Citadel of Thang Long is a historic site located in Hanoi, Vietnam. It served as the political center of various dynasties for over a thousand years, beginning in the Ly Dynasty in the 11th century. The citadel is recognized for its unique architecture and cultural significance, showcasing a blend of Vietnamese and Chinese influences. In 2010, the site was designated a UNESCO World Heritage Site due to its historical importance. The citadel features several notable structures, including the Flag Tower and the Royal Palace, which reflect the rich history and heritage of Vietnam. Visitors can explore its ancient walls and learn about its role in the country's past.