very flexible and able to withstand earthquakes, a phenomenon of nature with which Japan was already well acquainted during the Nara period. The Shōsō-in is also the only building to survive the Siege of Nara in the Heian period. The exact construction date is unclear, but construction works probably started soon after the empress's bequest in AD 756 and definitely were finished before AD 759, when the bequest items storage lists were complete. Preservation of the artifacts Since the Shōsō-in was to be a repository for (valuable) objects, it was constructed to create a natural climate regulation system. This natural climate regulation system was created by elevating the floor to a height of 2.7 m. This made circulation of air underneath the building possible and protected the structure against humidity at the same time. In addition to this, during the first few decades after its construction, the triangular beams of the Japanese cypress might have functioned as a natural regulator of humidity and temperature. The artefacts themselves were stored away in chests made from Cedar wood that's known for its durability. These chests were 90–110 cm long, 60–70 cm wide and 40–50 cm high. Not only the building itself but also these chests were elevated from the ground. All these adjustments made it possible to preserve the treasures in perfect state. Treasures The Shōsō-in today holds around 9,000 items, excluding items that are yet to be classified. The treasures that were donated by Empress Kōmyō were stored in the Hoku Sō, the Northern part of the Shōsōin. From the very beginning, this part of the Shōsō-in has been sealed by the imperial family. One was permitted to enter only with explicit permission of the imperial family. Ninety-five percent of the fine arts and crafts in the Shōsōin were produced in Japan around the 8th century, with the remainder imported from the Tang Dynasty, Central Asia, India, Iran, etc. during the same period. The designs of these Japanese and East Asian treasures show Iranian, Greek, Roman, and Egyptian influences due to cultural exchange via the Silk Road. Although these collections are not open to the public, selections are shown at Nara National Museum once a year in autumn. The objects and treasures that have been stored in the Shōsō-in can be divided into the following categories. Buddhist objects Clothing and accessories Furniture Games Music instruments Weaponry Documents Generally considered separate from