Astra Tower, Germany（德國雅特塔）

Built in the mid-13th century, the Astra Tower is a church in Hamburg, Germany. Its 27.43-meter(90-feet)-high spire made from oak, was added to the structure in 1450. Since then, the spire began to tilt because of the oak material and their wet foundations. Great efforts were made until the spire was finally fastened in 1996. Today the church is still in use and open to the public as a tourist site.