Na Yin Earth on the City Wall (城头土): the image of a pillar pair
Na Yin: Earth on the City Wall (城头土)
Na Yin assigns a poetic image to each consecutive pair of stem-branch combinations. "Earth on the City Wall" (Cheng Tou Tu) belongs to the pairs 戊寅 and 己卯.
How Na Yin is used
Traditional readers use Na Yin as a texture layer — an image for the quality of a pillar pair — rather than as a prediction. Different schools weight it differently.
Where you can see it
Build a chart on MingLens to see the Na Yin of your year pillar and check whether "Earth on the City Wall" appears in your structure.
Boundary
Na Yin images are cultural vocabulary, not statements of fact about a person.