The lunar craters Theophilus and Cyrillus are located on the northwest edge of Mare Nectaris. Together with Catharina, these three craters form a prominent trio in the southeast quadrant of the Moon.

The following photo shows Theophilus and Cyrillus with a stunning resolution. It was photographed by Swiss astrophotographer Peter Hugi on 11.03.2011. Hugi explores the night sky with a DMK 21AU04.AS astronomy camera, manufactured by The Imaging Source.