A wide variety of craters ranging in size from 100 meters to 1300 km across can be seen in the Mariner 10 images of Mercury's surface. These include: (1) craters in young terrain, (2) double craters, (3) craters with rays of material directed away from them ("ray craters"), (4) craters with peaks in the center, and (5) craters with smooth plains inside. The largest crater on the surface of the planet is the Caloris Basin.