Aerial photo taken on July 30, 2020 shows a worker checking blue bricks at a factory in Chu'an Town of Renqiu City, north China's Hebei Province. "Blue Brick" with a long history is one of the main building materials of ancient Chinese architecture. The brick factory in Chu'an Town, which was built on the basis of an ancient brick kiln in the Qing Dynasty (1644-1911), develops the traditional craftsmanship and mainly produces blue bricks and other building materials for antique buildings at present. (Xinhua/Mu Yu)

A worker stacks adobes of blue brick at a factory in Chu'an Town of Renqiu City, north China's Hebei Province, July 30, 2020. "Blue Brick" with a long history is one of the main building materials of ancient Chinese architecture. The brick factory in Chu'an Town, which was built on the basis of an ancient brick kiln in the Qing Dynasty (1644-1911), develops the traditional craftsmanship and mainly produces blue bricks and other building materials for antique buildings at present. (Xinhua/Mu Yu)

A worker stacks the unbaked tiles at the kiln in a factory in Chu'an Town of in Renqiu City, north China's Hebei Province, July 30, 2020. "Blue Brick" with a long history is one of the main building materials of ancient Chinese architecture. The brick factory in Chu'an Town, which was built on the basis of an ancient brick kiln in the Qing Dynasty (1644-1911), develops the traditional craftsmanship and mainly produces blue bricks and other building materials for antique buildings at present. (Xinhua/Mu Yu)

A worker makes adobes of blue brick at a factory in Chu'an Town of Renqiu City, north China's Hebei Province, July 30, 2020. "Blue Brick" with a long history is one of the main building materials of ancient Chinese architecture. The brick factory in Chu'an Town, which was built on the basis of an ancient brick kiln in the Qing Dynasty (1644-1911), develops the traditional craftsmanship and mainly produces blue bricks and other building materials for antique buildings at present. (Xinhua/Mu Yu)

Aerial photo taken on July 30, 2020 shows a worker transporting adobes of blue brick at a factory in Chu'an Town of Renqiu City, north China's Hebei Province. "Blue Brick" with a long history is one of the main building materials of ancient Chinese architecture. The brick factory in Chu'an Town, which was built on the basis of an ancient brick kiln in the Qing Dynasty (1644-1911), develops the traditional craftsmanship and mainly produces blue bricks and other building materials for antique buildings at present. (Xinhua/Mu Yu)