A surveying point of the Geospatial Information Authority of Japan. The plaque shows a map of Japan and an illustration of a surveyor with a measuring instrument.
Similar plaques are found throughout Japan and serve as a basis for surveying and mapping the country.
Translation of the text on the cover: 水準点 基本 - Basic Standard point 建設省国土地理院 - Ministry of Construction, Geospatial Information Authority of Japanן