南京城墙, or the Nanjing City Wall, is a historic fortification located in Nanjing, China. Built during the Ming Dynasty in the 14th century, it stretches approximately 35 kilometers and is one of the longest city walls in the world. The wall was constructed using local materials and served as a defense mechanism against invasions. The Nanjing City Wall features several gates, watchtowers, and battlements, showcasing ancient military architecture. It has been recognized as a significant cultural heritage site and attracts many visitors who come to explore its rich history and enjoy scenic views of the surrounding area.