The origin of Shuri Castle is not known exactly, but it is believed to have been built by Satto, the king of Chuzan, toward the end of the 14th century. For the next 450 years, until the Ryukyu Kingdom was abolished in 1879 and the last Sho king, King Sho-tai, surrendered the castle to the Meiji government, it was the focus of political and religious life in Ryukyu. The Houshin-Mon inner gate to the castle opens onto a spacious courtyard, or plaza, called Unaa. All kinds of ceremonies and rituals were held in the courtyard, but certainly the most splendid were royal coronations when envoys came from the Chinese emperor to certify the royal succession. Besides the large dragon pillar, twenty-three other dragons are found throughout Shuri Castle. The seiden (main hall) is built of wood blending Ryukyu, Japanese, and Chinese styles. It has a hip-gable roof, while the entryway is roofed in the Chinese gable style.