is a
Lunar Crater located in the western part of the
Moon , near the limb. As a result the Byrgius crater appears strongly oval in form due to foreshortening. To the northwest is the nearly ruined
Lamarck Crater . The rim of Byrgius is worn and eroded, with the 'Byrgius A' crater overlaying the eastern rim and 'Byrgius D' laying across the northwest. The floor is relatively flat and undistinguished by significant craterlets. The crater 'Byrgius A' possesses its own
Ray System that have a radius of over 400
Kilometer s.
By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Byrgius crater.
