For Wu, ancient pagodas are not by any means just a pile of rocks or bricks, but old friends that he has not seen for a long time.

"Every time I visit an ancient pagoda, I see not only a cultural heritage item lasting for centuries and the beauty of architecture, but also the simple hearts pursuing perfection and revering nature that, however, have been lost in the hustle and bustle of modern life," he writes in the introduction.

"Although originating from ancient India, unlike stupas, Chinese ancient pagodas are charming for their rich diversity," he writes.

The pagodas built in different historical periods and regions exhibit unique characteristics. Throughout a development of nearly 2,000 years, pagodas have undergone countless changes in form, showcasing a multitude of styles.

"Across the 9.6 million square kilometers of land in China, among the over 10,000 existing pagodas, no two are completely identical," he writes.