Aerial photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial panoramic photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows tourists visiting the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows tourists visiting the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows a view of the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)

Aerial photo taken on Oct. 24, 2020 shows tourists visiting the Badaling Great Wall in Beijing, capital of China. The Badaling Great Wall is a major tourist attraction for autumn views in Beijing. (Xinhua/Chen Yehua)