Ancient China's graves are generally buried in which direction?

The shape of the imperial mausoleums was inherited from the imperial tombs of the Northern Song Dynasty, and basically still follows the old system since the Han and Tang dynasties. The ancestral mausoleum in Sizhou is a little later, and its shape is already similar to that of Zhu Yuanzhang's Xiaoling Mausoleum in Nanjing, while the Ming Xiaoling Mausoleum set a precedent for the Ming Dynasty mausoleum system thereafter. During the Ming Dynasty, 13 emperors, starting with Zhu Di, the founder of the Ming Dynasty, were buried in Changping County, Beijing, in a general mausoleum called the Ming Thirteen Mausoleums. The main gate of the mausoleum is in the south, called the Dahongmen. Not far from the main gate, there is the "Monument of Divine Merit and Sacred Virtue of the Changling Mausoleum". From the Pavilion to the north, the Divine Path on both sides of the stone columns and lions, Xiezhi, camels, elephants, unicorns, horses, military generals, civil servants and other stone statues, and the mausoleum before the stone columns and stone elephants are no longer standing. For general layout considerations, the direction of the mausoleum is mostly to the south, but also to the east or west. The size of each mausoleum varies, but the shape and layout are the same as each other. The front of the mausoleum is mainly the Hall of Grace, basically equivalent to the Tang and Song dynasty mausoleum before the dedication of the hall (see color Beijing Changping Ming Changling Hall of Grace show pictures). Compared with the emperor's mausoleum since the Han and Tang dynasties, the Ming mausoleum's biggest feature is that the mound is not square and round, surrounded by brick walls, known as Bao Cheng, its location is not in the middle of the mausoleum area in the whole mausoleum at the end of the last. Treasure city before the Ming building, upstairs tree stone monument, engraved on the emperor's posthumous name, which is also a new creation of the Ming mausoleum. Xuan Gong in the treasure city, the shape of the palace is also imitated. To have been excavated Ming Dingling mausoleum, for example, the palace can be divided into the front hall, the middle hall and the back of the hall, the middle of the left and right sides of the hall and each through a hall. The emperor and the empress of the coffin placed in the back of the coffin bed