|Lat: 80.3°N, Long: 113.5°E, Diam: 43 km, Depth: , Rükl: (farside)|
- Cai Lun is partially visible from Earth when the librations are favorable. In this geocentric view from August 14, 2010 at 04:00 UT (the peak of the first favorable libration after its naming), simulated with LOLA DEM data, part of its shadowed floor can be seen beyond Nansen. The recently named crater Houssay is also nicely visible. Observers in the Earth's northern hemisphere will see Cai Lunslightly more onto the lunar disk, those in the southern hemisphere less so.
- Named for Cai Lun (c. 57-121), a Chinese inventor credited with the invention of paper.
- This name for a previously unnamed crater was approved by the IAU on August 2, 2010.