At the heart of this complex lies the Perfume Temple or Perfume Pagoda in the Huong Tich Cave.
It features a restaurant and non-smoking rooms with a flat-screen TV.
There is also a spa resort nestled at the foot of the mountain offering a host of natural therapies in an absolutely stunning setting.
The three mountain summits are Dinh Vua which is the highest at 1,296m, Tan Vien which is 1,226m and Ngoc Hoa the smallest at 1,131m.
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.
It offers French-colonial architecture, a rich food culture and a long history (the city celebrated its millennium in 2010.) The most well known and important districts in Hanoi are Ba Dinh District (aka the French Quarter) where the government offices are located and Hoan Kiem District (aka the Old Quarter) which is considered the citys most famous areas of outstanding natural beauty, and is centered around a three-peaked mountain jutting steeply out of the landscape.