Atget crater is located within Caloris basin, near Apollodorus crater and Pantheon Fossae. The dark color of the floor is in contrast to other craters within Caloris basin that exhibit bright materials on their floors, such as the craters Kertész and Sander. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Mercury they are named after deceased artists, musicians, painters, and authors who have made outstanding or fundamental contributions to their field and have been recognized as art historically significant figures for more than 50 years.
Image Source. Marker locations are approximate and may not always appear to align with image on map.