The Imperial Citadel of Thang Long, is an intriguing relic of Vietnam’s history and, signifying its historical and cultural importance, was made a UNESCO World Heritage Site in 2010. Also known as the Hanoi Citadel, many artefacts and items dating back to between the 6th and 20th centuries were excavated in 2004, including foundations of old palaces, ancient roads, ponds and wells.
On top of these discoveries, archaeologists also found bronze coins, ceramics and pottery from China and many places in Asia, all of which demonstrate a close trading relationship in the area. Visitors should head for the display room that features interesting excavated items and mock-ups of the citadel itself.
http://www.vietnam-guide.com/hanoi/imperial-citadel.htm