The ancestral pole is located at the southeast side of the Kunning Palace, which is the northeast corner of the Hall of Union. The catalog number is No. 00204055, and is recorded as a Manchurian pole for offering sacrifices to the gods. Now only the pedestal of the sacred pole exists.
The sacred pole is called “Soluo” in Manchu, and there is also the saying of Soluo’s sacred pole. The shape of the pole is shown in figure 6. The debate continues as to whether the sacred pole should be used for ancestor worship or for offering sacrifices to the gods .
The sacred pole outside the palace, also known as the Ancestral Pole. According to the Manchu custom, when offering sacrifices to heaven, the altar table is placed in the northeast of the sacred pole. On the altar were neck bones, gall bladders, shredded meat and rice. When the sacrifice is over, place the neck bone at the top of the pole, the gallbladder, shredded pork and rice into a bowl, and then the emperor and Queen prayed for blessings. 
In Qing Dynasty, the Kun Ning Palace was rebuilt and renovated three times according to the Manchu style in Shunzhi 12th year (1655) , Kangxi 19th year (1680) and Jiaqing 3rd year (1798) . As for when the sacred pole began to erect in the Palace, there is no record found. However, the ancestral poles can be seen from the photos of 1900-1925 (Fig. 6-Fig. 9). The pole is missing from the 1982 photo. The specific age of erecting and removing the ancestral sacred pole remains to be verified.
According to the Sikuquanshu, the sacred pole was taken from the pine trees of Yanqing District. Click to view details.
故宫丛刊之三 故宫摄影集 第一编第二册 交泰殿坤宁宫 清室善后委员会 30页