For centuries, Hanoi Citadel was only accessible to the country’s rulers, but in 2010, it was recognized by UNESCO as a World Heritage Site and is now open to the public. Unfortunately, much of the site was destroyed by the French in the late 19th century, however, the surviving buildings are worth a visit.
At the south end of this mammoth complex, adjacent to the Military History Museum is the Cat Co, or the Flag Tower. North of here, the Doan Mon Gate is probably the most impressive structure of the Citadel still remaining. The imposing walls containing five archways and supporting a double-roofed pavilion can be seen once the main entrance to the forbidden realm is entered. Beyond the gate are the excavations showing a sophisticated waterway, probably once used for irrigation. Nothing remains of the Kinh Tien Palace, which once functioned as the imperial residence, apart from its beautifully sculpted dragon balustrades.
In the heart of the complex is a squat colonial building named D67, which was a command center for northern forces during the Vietnam War. The conference table still has the reserved seats of luminaries such as General Giap (1911–2013), who was the mastermind behind many Vietnamese victories. There is also a bomb shelter deep below the ground.
North of the D67 building are two more structures of interest– Hau Lau and Cua Bac, the northern gate. However, on the west side of Hoang Dieu Street is a massive archaeological dig, consisting mostly of foundations of former palaces, that gives an idea of the enormous scale of the Citadel.