St. John is an eroded lunarimpact crater on the Moon's far side. This crater is situated to the northeast of the huge walled plain Mendeleev, and southwest of the crater Kohlschütter. To the east of St. John is the small crater Mills.
This is a heavily worn and eroded crater formation that is now little more than an uneven depression in the surface. It is scarcely distinguishable from the surrounding terrain, except from the shadows cast by the outer rim. The interior floor is uneven and marked by a chain of three small craterlets near the midpoint.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763. S2CID122125855.