Mysterious ancient monuments aligning with the heavens might sound like the stuff of conspiracy theorists and badly-edited YouTube videos, however, this idea is actually not far from the truth when it comes to ancient China.

Recent research by the Politecnico di Milano in Italy has shown how dozens of the ancient Chinese imperial mausoleums and pyramids align with "great precision" to astronomical points of interest, as reported in the journal Archaeological Research in Asia. While we regret to report that this is not evidence of extra-terrestrial involvement in their construction, it does reveal how the ancient Chinese dynasties paid close attention to astronomy and combined it with their traditional concepts of feng shui.

Giulio Magli, an Italian archaeoastronomer, used satellite images to unravel the “spatial and cognitive relationships” between the mausoleums of the Emperors and royal family members of the Western Han Chinese Dynasty dotted around the outskirts of the city Xi'an along China's Wei River.

In this region, we find over 40 "Chinese pyramids", tombs of someone of royal blood lying beneath an artificial hill. According to Magli, this style is directly inspired by some of the world’s most awe-inspiring monuments, the great mausoleums of China's first Emperor, Qin Shi Huang, and his terracotta army. Qin united China in 221 BCE, gave it its name (Qin is pronounced "chin"), and ruled directly before the Han dynasty took the throne.

Magli says the burials were inspired by the burial site of the first Emperor of Qin, which is famously guarded by the Terracotta Army. Giulio Magli

Just like the Egyptian pyramids, it appears that the Chinese emperors aligned their burial mounds to the cardinal points of north, east, south, and west. This attention to detail is understandable when you consider the emperors’ beliefs that their power was a direct mandate of the heavens, plus the traditional use of feng shui to orientate objects in an auspicious manner.

Although around half of these monuments were aligned precisely to true north, Magli noted that a select few others follow a slightly different pattern of orientation, "off" by nearly 14 degrees.

This is not due to human error, he argues. Although the first compasses were invented at this time, it’s believed the monuments were not aligned using paleomagnetic information from a directional compass. Instead, they used information directly from the stars, which can be a little complex at times.

An effect called the precession of the equinoxes explains how our planet’s rotational axis slowly shifts over long periods of time, causing the position of the stars to move in the night sky. When the slightly off mausoleums were being placed, no clear star aligned to the north celestial pole. In the eyes of their traditions, it wouldn’t be satisfactory to align the structure to the north celestial pole, as it did not have a corresponding star.

Fortunately, they had a solution. To fix this problem, it appears that this set of monuments were instead aligned with the star to which the pole would be approached in the future, Polaris, aka the North Star. Clever, eh?