The First and the Second Daigokuden of the Heijo-kyu Palace were significantly different in structure; the Hanyuan Hall of the Daming Palace in Chang'an at the time of the Tang Dynasty in China had a strong influence on the First Daigokuden, which had a large front garden and was built elevated one step from the garden, and this was in turn a prototype of the Ryubidan (stone steps of the Heiangu Palace to the south of Daigokuden).
平城宮大極殿は第一次と第二次とで大きく構造が異なり、第一次では唐長安大明宮含元殿の影響を受け、大極殿院が広い前庭を持ち、また大極殿は前庭から1段高い位置に建設されており、平安宮の龍尾壇（竜尾壇りゅうびだん）の原型といえる。