Tourists are seen at the Qujiang New District in Xi'an, capital of Northwest China's Shaanxi province, Feb 5, 2019. [Photo/Xinhua]

Photo shows the night view of the Qujiangchi Park in Xi'an, capital of Northwest China's Shaanxi province, Feb 9, 2019. [Photo/Xinhua]

Tourists visit the decorated Kaiyuan Square in Xi'an, capital of Northwest China's Shaanxi province, Feb 5, 2019. [Photo/Xinhua]

Tourists visit the decorated Kaiyuan Square in Xi'an, capital of Northwest China's Shaanxi province, Feb 5, 2019. [Photo/Xinhua]

Tourists visit an ancient city wall in Xi'an, capital of Northwest China's Shaanxi province, Feb 7, 2019. [Photo/Xinhua]

Tourists visit an ancient city wall in Xi'an, capital of Northwest China's Shaanxi province, Feb 7, 2019. [Photo/Xinhua]