Why a 1,000-year-old wooden tower survived earthquakes and cannons but not a repair job

Earthquakes hit it. Cannons hit it. For nearly a thousand years, the Yingxian wooden pagoda in northern China refused to fall: 220 feet of interlocking timber with no metal nails, built in 1056. Its secret is sharing the shake. Sliding wooden brackets called dougong move together, and hidden braced floors alternate with open ones, stiff, flexible, stiff, flexible. Then, in the 1930s, a repair pulled out key braces and mud walls and put in doors. Within fifteen years the tower was leaning. Today one second-floor column is almost two feet out of line, and the plan is to ease it back toward vertical by 2056, the tower's thousandth birthday. Sources: • Guinness World Records, Towering wooden pagoda in China (2016) · https://www.guinnessworldrecords.com/news/2016/9/guinness-world-records-awards-record-certificate-for-towering-wooden-pagoda-in-ch-445332 • The Paper — China Academy of Cultural Heritage report on the Yingxian pagoda (2020) · https://www.thepaper.cn/newsDetail_forward_9636739