The ancient compass was formed by the deflection of the magnetic needle in the geomagnetic field, so its direction meets the direction of the modern compass, which points to the geomagnetic south pole and the geomagnetic north pole. Some places contain magnetite and a large number of iron products underground, which will lead to geomagnetic anomalies in this area. At this time, the compass direction will change. According to Feng Shui, this place is not suitable for people's life. This does have some impact, but it has little impact.