The Luo Pan is a complex Chinese compass with up to 40 concentric rings used to align structures with natural energy.

The Luo Pan, also known as a Feng Shui compass, represents centuries of Chinese astronomical and magnetic observations. While the magnetic compass was invented in China during the Han Dynasty between 206 BC and 220 AD, the specialized Luo Pan evolved significantly during the Song Dynasty. It consists of a central magnetic needle called the 'Heaven Pool' surrounded by a wooden plate featuring complex concentric rings.Each ring on a Luo Pan serves as a data layer for a Feng Shui master. These rings include the 24 Mountains, which divide the 360 degrees of a circle into 15-degree segments, and the I Ching trigrams. Modern versions can feature up to 40 or more rings, incorporating the 28 Lunar Mansions and the 60-year sexagenary cycle. This allows practitioners to align human-made structures with both the Earth's magnetic field and celestial patterns.The tool is used to determine the orientation of a building to maximize the flow of 'Qi,' or vital energy. Research by scholars like Joseph Needham has highlighted the Luo Pan as a precursor to modern scientific instruments because of its precision in measuring magnetic declination. Today, it remains a vital instrument in traditional Chinese architecture and urban planning, used to ensure that the layout of a space promotes health, wealth, and balance for its occupants.