Miyamoto is a crater lying situated within the Margaritifer Sinus quadrangle region of the planet Mars, west of the Plains of Meridiani. The crater is 150 kilometers wide. The crater's northeastern half is filled with rocks formed in the presence of water and include minerals of iron and sulfur, which likely settled on lake bottoms or in groundwater systems. In the southwestern half of the crater floor, erosion has stripped these materials away, instead revealing clays and other materials like those found in the most ancient Martian rocks. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Mars large craters are named after deceased scientists, writers and others who have contributed to the lore of Mars. Small creaters (less than 60km) are named after small towns and villages.