Sander is a crater on Mercury, within Caloris Basin. It has dark walls and bright patches on its floor. Unlike the rays of Basho crater, the bright areas are not believed to be immature but are inherently bright. (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.