Aerial photo taken on Jan. 1, 2021 shows the sunset scenery of Dayan Pagoda in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Jan. 1, 2021 shows people visiting the ancient city wall at sunset in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Jan. 1, 2021 shows people visiting the ancient city wall at sunset in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Jan. 1, 2021 shows the sunset scenery of Dayan Pagoda in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Jan. 1, 2021 shows people visiting the ancient city wall at sunset in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Jan. 1, 2021 shows the sunset scenery in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Jan. 1, 2021 shows the sunset scenery in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Jan. 1, 2021 shows people visiting the ancient city wall at sunset in Xi'an, northwest China's Shaanxi Province. (Xinhua/Tao Ming)