Nanjing's tower of strength

The construction of the Porcelain Pagoda in Nanjing, Jiangsu province, was ordered by the Emperor Yongle during the Ming Dynasty (1368-1644) to express his gratitude to his mother. The Grand Bao'en Temple, where the pagoda is located, literally means "Temple of Repaid Kindness".

It took the country's best architects 17 years to complete the 78.2-meter-high octagonal structure, which was covered by colorful glazed porcelain bricks made by the most skillful workers of the time. The building was renowned as one of the seven wonders of the medieval world.

Zhou Daoxiang, former curator of the Imperial Examination Museum of China in Nanjing, said the largest bricks in the pagoda could weigh as much as 150 kilograms each.