The Forbidden Purple City found in Hue, Vietnam is more than just a tourist attraction, its living history. Built for the Nguyen Dynasty, the entire city is surrounded by a 10km moat and 10 gates. The city is laid out so that there is a citadel within a citadel within a citadel. The first citadel of the city was populated by non-royal commoners. The next was built for important ceremonies. The final citadel is where the Purple Forbidden City was located.