Gyantse Fortress

Gyantse Dzong or Gyantse Fortress is one of the best preserved dzongs in Tibet, perched high above the town of Gyantse on a huge spur of grey brown rock.

According to Vitali, the fortress was constructed in 1390 and guarded the southern approaches to the Tsangpo Valley and Lhasa. The town was surrounded by a wall 3 kilometres long. The entrance is on the eastern side.

Source: Wikipedia